source: tests/list/dlist-insert-remove.cfa@ 6136ecc

#include <containers/list.hfa>
#include <fstream.hfa>
#include <assert.h>

// Section 1:  replaced by above include list.hfa


////////////////////////////////////////////////////////////
//
// Section 2
//
// Structure definitions
//
// Example of declaration-side user code
//
////////////////////////////////////////////////////////////

// a fred belongs to two doubly-linked lists: mine and yours
struct fred {
        float adatum;
        DLISTED_MGD_EXPL_IN(fred, mine)
        DLISTED_MGD_EXPL_IN(fred, yours)
};

DLISTED_MGD_EXPL_OUT(fred, mine)
DLISTED_MGD_EXPL_OUT(fred, yours)

void ?{}(fred &this, float adatum) {
        (this.adatum){adatum};
}

// a mary belongs to just one doubly-linked list: hers
struct mary {
        float anotherdatum;
        DLISTED_MGD_IMPL_IN(mary)
};

DLISTED_MGD_IMPL_OUT(mary)

void ?{}(mary &this, float anotherdatum) {
        (this.anotherdatum){anotherdatum};
}

////////////////////////////////////////////////////////////
//
// Section 3
//
// Test helpers to traverse and print lists.
//
// These consume framework-provided accessor functions and
// do not modify their parameter lists.
//
////////////////////////////////////////////////////////////

void printMyFredsFwd(fred &f) {
        while (&f != 0p) {
                sout | f.adatum;
                &f = &f`in_mine`next;
        }
}

void printMyFredsRev(fred &f) {
        while (&f != 0p) {
                sout | f.adatum;
                &f = &f`in_mine`prev;
        }
}

void printMyFreddies(fred &f1, fred &f2, int isBefore) {
        if (isBefore) {
                sout | "==== fred by MINE before ";
        } else {
                sout | "==== fred by MINE after ";
        }
        printMyFredsFwd(f1);    sout | '-';
        printMyFredsRev(f1);    sout | '-';
        printMyFredsFwd(f2);    sout | '-';
        printMyFredsRev(f2);    sout | '-';
}

void printYourFredsFwd(fred &f) {
        while (&f != 0p) {
                sout | f.adatum;
                &f = &f`in_yours`next;
        }
}

void printYourFredsRev(fred &f) {
        while (&f != 0p) {
                sout | f.adatum;
                &f = &f`in_yours`prev;
        }
}

void printYourFreddies(fred &f1, fred &f2, int isBefore) {
        if (isBefore) {
                sout | "==== fred by YOURS before ";
        } else {
                sout | "==== fred by YOURS after ";
        }
        printYourFredsFwd(f1);  sout | '-';
        printYourFredsRev(f1);  sout | '-';
        printYourFredsFwd(f2);  sout | '-';
        printYourFredsRev(f2);  sout | '-';
}

void printMariesFwd(mary &m) {
        while (&m != 0p) {
                sout | m.anotherdatum;
                &m = &m`next;
        }
}

void printMariesRev(mary &m) {
        while (&m != 0p) {
                sout | m.anotherdatum;
                &m = &m`prev;
        }
}

void printMariatheotokos(mary &m1, mary &m2, int isBefore) {
        if (isBefore) {
                sout | "==== mary before ";
        } else {
                sout | "==== mary after ";
        }
        printMariesFwd(m1);     sout | '-';
        printMariesRev(m1);     sout | '-';
        printMariesFwd(m2);     sout | '-';
        printMariesRev(m2);     sout | '-';
}

////////////////////////////////////////////////////////////
//
// Section 4a.i
//
// Test cases of insert_after on headless list
//
// Example of call-side user code
//
////////////////////////////////////////////////////////////

// All three tests exercise the case of merging two singleton lists into (their respective
// positions in) one common list of two elements.

// Note that the factoring of sect 4 (vs 3 and 5) keeps section 4 free of strings and IO,
// and so keeps its assembly easy to inspect.

// Throughout all the 4s, all the print functions called from these tests print:
//  - from list position #1 moving forward  (a)
//  - from list position #1 moving backward (b)
//  - from list position #2 moving forward  (c)
//  - from list position #2 moving backward (d)
// The expected-output comments are in form a;b;c;d where a::=num,num,num

void test__insertafter_singleton_on_singleton__fred_mine () {
        fred f1 = {3.14};
        fred f2 = {0.5};

        printMyFreddies(f1, f2, 1);     // 3.14; 3.14; 0.5; 0.5
        printYourFreddies(f1, f2, 1);   // 3.14; 3.14; 0.5; 0.5

        insert_after(f1`in_mine, f2);

        printMyFreddies(f1, f2, 0);     // 3.14, 0.5; 3.14; 0.5; 0.5, 3.14 (modified)
        printYourFreddies(f1, f2, 0);   // 3.14; 3.14; 0.5; 0.5 (unmodified)
}

void test__insertafter_singleton_on_singleton__fred_yours () {
        fred f1 = {3.14};
        fred f2 = {0.5};

        printMyFreddies(f1, f2, 1);     // 3.14; 3.14; 0.5; 0.5
        printYourFreddies(f1, f2, 1);   // 3.14; 3.14; 0.5; 0.5

        insert_after(f1`in_yours, f2);

        printMyFreddies(f1, f2, 0);     // 3.14; 3.14; 0.5; 0.5 (unmodified)
        printYourFreddies(f1, f2, 0);   // 3.14, 0.5; 3.14; 0.5; 0.5, 3.14 (modified)
}

void test__insertafter_singleton_on_singleton__mary () {
        mary m1 = {3.14};
        mary m2 = {0.5};

        printMariatheotokos(m1, m2, 1); // 3.14; 3.14; 0.5; 0.5

        insert_after(m1, m2);

        printMariatheotokos(m1, m2, 0); // 3.14, 0.5; 3.14; 0.5; 0.5, 3.14 (modified)
}

////////////////////////////////////////////////////////////
//
// Section 4a.ii
//
// Test cases of insert_before on headless list
//
// Example of call-side user code
//
////////////////////////////////////////////////////////////

void test__insertbefore_singleton_on_singleton__fred_mine () {
        fred f1 = {3.14};
        fred f2 = {0.5};

        printMyFreddies(f1, f2, 1);     // 3.14; 3.14; 0.5; 0.5
        printYourFreddies(f1, f2, 1);   // 3.14; 3.14; 0.5; 0.5

        insert_before(f2`in_mine, f1);

        printMyFreddies(f1, f2, 0);     // 3.14, 0.5; 3.14; 0.5; 0.5, 3.14 (modified)
        printYourFreddies(f1, f2, 0);   // 3.14; 3.14; 0.5; 0.5 (unmodified)
}

void test__insertbefore_singleton_on_singleton__fred_yours () {
        fred f1 = {3.14};
        fred f2 = {0.5};

        printMyFreddies(f1, f2, 1);     // 3.14; 3.14; 0.5; 0.5
        printYourFreddies(f1, f2, 1);   // 3.14; 3.14; 0.5; 0.5

        insert_before(f2`in_yours, f1);

        printMyFreddies(f1, f2, 0);     // 3.14; 3.14; 0.5; 0.5 (unmodified)
        printYourFreddies(f1, f2, 0);   // 3.14, 0.5; 3.14; 0.5; 0.5, 3.14 (modified)
}

void test__insertbefore_singleton_on_singleton__mary () {
        mary m1 = {3.14};
        mary m2 = {0.5};

        printMariatheotokos(m1, m2, 1); // 3.14; 3.14; 0.5; 0.5

        insert_before(m2, m1);

        printMariatheotokos(m1, m2, 0); // 3.14, 0.5; 3.14; 0.5; 0.5, 3.14 (modified)
}

////////////////////////////////////////////////////////////
//
// Section 4b.i
//
// Test cases of insert_first (necessarily headed list)
//
// Example of call-side user code
//
////////////////////////////////////////////////////////////

// All three tests exercise the case of creating an empty container and
// adding two items to it.

void test__insertfirst_two_on_empty__fred_mine() {

        fred f1 = {3.14};
        fred f2 = {0.5};

        dlist(fred_in_mine, fred) lf;

        printMyFreddies(f1, f2, 1);     // 3.14; 3.14; 0.5; 0.5
        printYourFreddies(f1, f2, 1);   // 3.14; 3.14; 0.5; 0.5

        insert_first(lf, f2);
        insert_first(lf, f1);

        printMyFreddies(f1, f2, 0);     // 3.14, 0.5; 3.14; 0.5; 0.5, 3.14 (modified)
        printYourFreddies(f1, f2, 0);   // 3.14; 3.14; 0.5; 0.5 (unmodified)
}

void test__insertfirst_two_on_empty__fred_yours() {

        fred f1 = {3.14};
        fred f2 = {0.5};

        dlist(fred_in_yours, fred) lf;

        printMyFreddies(f1, f2, 1);     // 3.14; 3.14; 0.5; 0.5
        printYourFreddies(f1, f2, 1);   // 3.14; 3.14; 0.5; 0.5

        insert_first(lf, f2);
        insert_first(lf, f1);

        printMyFreddies(f1, f2, 0);     // 3.14; 3.14; 0.5; 0.5 (unmodified)
        printYourFreddies(f1, f2, 0);   // 3.14, 0.5; 3.14; 0.5; 0.5, 3.14 (modified)
}

void test__insertfirst_two_on_empty__mary() {

        mary m1 = {3.14};
        mary m2 = {0.5};

        dlist(mary, mary) lm;

        printMariatheotokos(m1, m2, 1); // 3.14; 3.14; 0.5; 0.5

        insert_first(lm, m2);
        insert_first(lm, m1);

        printMariatheotokos(m1, m2, 0); // 3.14, 0.5; 3.14; 0.5; 0.5, 3.14 (modified)
}

////////////////////////////////////////////////////////////
//
// Section 4b.ii
//
// Test cases of insert_last (necessarily headed list)
//
// Example of call-side user code
//
////////////////////////////////////////////////////////////

void test__insertlast_two_on_empty__fred_mine() {

        fred f1 = {3.14};
        fred f2 = {0.5};

        dlist(fred_in_mine, fred) lf;

        printMyFreddies(f1, f2, 1);     // 3.14; 3.14; 0.5; 0.5
        printYourFreddies(f1, f2, 1);   // 3.14; 3.14; 0.5; 0.5

        insert_last(lf, f1);
        insert_last(lf, f2);

        printMyFreddies(f1, f2, 0);     // 3.14, 0.5; 3.14; 0.5; 0.5, 3.14 (modified)
        printYourFreddies(f1, f2, 0);   // 3.14; 3.14; 0.5; 0.5 (unmodified)
}

void test__insertlast_two_on_empty__fred_yours() {

        fred f1 = {3.14};
        fred f2 = {0.5};

        dlist(fred_in_yours, fred) lf;

        printMyFreddies(f1, f2, 1);     // 3.14; 3.14; 0.5; 0.5
        printYourFreddies(f1, f2, 1);   // 3.14; 3.14; 0.5; 0.5

        insert_last(lf, f1);
        insert_last(lf, f2);

        printMyFreddies(f1, f2, 0);     // 3.14; 3.14; 0.5; 0.5 (unmodified)
        printYourFreddies(f1, f2, 0);   // 3.14, 0.5; 3.14; 0.5; 0.5, 3.14 (modified)
}

void test__insertlast_two_on_empty__mary() {

        mary m1 = {3.14};
        mary m2 = {0.5};

        dlist(mary, mary) lm;

        printMariatheotokos(m1, m2, 1); // 3.14; 3.14; 0.5; 0.5

        insert_last(lm, m1);
        insert_last(lm, m2);

        printMariatheotokos(m1, m2, 0); // 3.14, 0.5; 3.14; 0.5; 0.5, 3.14 (modified)
}

////////////////////////////////////////////////////////////
//
// Section 4c.i
//
// Test cases of insert_after on headed list
//
// Example of call-side user code
//
////////////////////////////////////////////////////////////

void test__insertafter_after_last__fred_mine() {

        fred f1 = {3.14};
        fred f2 = {0.5};

        dlist(fred_in_mine, fred) lf;

        assert(& lf`first == 0p);
        assert(& lf`last == 0p);

        insert_first(lf, f1);

        assert(& lf`first == & f1);
        assert(& lf`last == & f1);

        insert_after(f1`in_mine, f2);

        printMyFreddies(f1, f2, 0);     // 3.14, 0.5; 3.14; 0.5; 0.5, 3.14 (modified)
        printYourFreddies(f1, f2, 0);   // 3.14; 3.14; 0.5; 0.5 (unmodified)

        assert(& lf`first == & f1);
        assert(& lf`last == & f2);
}

void test__insertafter_after_last__fred_yours() {

        fred f1 = {3.14};
        fred f2 = {0.5};

        dlist(fred_in_yours, fred) lf;

        assert(& lf`first == 0p);
        assert(& lf`last == 0p);

        insert_first(lf, f1);

        assert(& lf`first == & f1);
        assert(& lf`last == & f1);

        insert_after(f1`in_yours, f2);

        printMyFreddies(f1, f2, 0);     // 3.14; 3.14; 0.5; 0.5 (unmodified)
        printYourFreddies(f1, f2, 0);   // 3.14, 0.5; 3.14; 0.5; 0.5, 3.14 (modified)

        assert(& lf`first == & f1);
        assert(& lf`last == & f2);
}

void test__insertafter_after_last__mary() {

        mary m1 = {3.14};
        mary m2 = {0.5};

        dlist(mary, mary) lm;

        assert(& lm`first == 0p);
        assert(& lm`last == 0p);

        insert_first(lm, m1);

        assert(& lm`first == & m1);
        assert(& lm`last == & m1);

        insert_after(m1, m2);

        printMariatheotokos(m1, m2, 0); // 3.14, 0.5; 3.14; 0.5; 0.5, 3.14 (modified)

        assert(& lm`first == & m1);
        assert(& lm`last == & m2);
}

////////////////////////////////////////////////////////////
//
// Section 4c.ii
//
// Test cases of insert_before on headed list
//
// Example of call-side user code
//
////////////////////////////////////////////////////////////

void test__insertbefore_before_first__fred_mine() {

        fred f1 = {3.14};
        fred f2 = {0.5};

        dlist(fred_in_mine, fred) lf;

        assert(& lf`first == 0p);
        assert(& lf`last == 0p);

        insert_last(lf, f2);

        assert(& lf`first == & f2);
        assert(& lf`last == & f2);

        insert_before(f2`in_mine, f1);

        printMyFreddies(f1, f2, 0);     // 3.14, 0.5; 3.14; 0.5; 0.5, 3.14 (modified)
        printYourFreddies(f1, f2, 0);   // 3.14; 3.14; 0.5; 0.5 (unmodified)

        assert(& lf`first == & f1);
        assert(& lf`last == & f2);
}

void test__insertbefore_before_first__fred_yours() {

        fred f1 = {3.14};
        fred f2 = {0.5};

        dlist(fred_in_yours, fred) lf;

        assert(& lf`first == 0p);
        assert(& lf`last == 0p);

        insert_last(lf, f2);

        assert(& lf`first == & f2);
        assert(& lf`last == & f2);

        insert_before(f2`in_yours, f1);

        printMyFreddies(f1, f2, 0);     // 3.14; 3.14; 0.5; 0.5 (unmodified)
        printYourFreddies(f1, f2, 0);   // 3.14, 0.5; 3.14; 0.5; 0.5, 3.14 (modified)

        assert(& lf`first == & f1);
        assert(& lf`last == & f2);
}

void test__insertbefore_before_first__mary() {

        mary m1 = {3.14};
        mary m2 = {0.5};

        dlist(mary, mary) lm;

        assert(& lm`first == 0p);
        assert(& lm`last == 0p);

        insert_last(lm, m2);

        assert(& lm`first == & m2);
        assert(& lm`last == & m2);

        insert_before(m2, m1);

        printMariatheotokos(m1, m2, 0); // 3.14, 0.5; 3.14; 0.5; 0.5, 3.14 (modified)

        assert(& lm`first == & m1);
        assert(& lm`last == & m2);
}

////////////////////////////////////////////////////////////
//
// Section 4d.i
//
// Test cases of remove, from middle of headless list
//
// Example of call-side user code
//
////////////////////////////////////////////////////////////

// These tests, in the fred cases, set up the my/your lists initially identical,
// act on one list, and expect the other unaffected.

void test__remove_mid__fred_mine() {

        fred f1 = {1.7};
        fred f2 = {2.7};
        fred f3 = {3.7};

        insert_after(f1`in_mine, f2);
        insert_after(f2`in_mine, f3);

        insert_after(f1`in_yours, f2);
        insert_after(f2`in_yours, f3);

        printMyFreddies(f1, f3, 1);     // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 
        printYourFreddies(f1, f3, 1);   // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 

        remove(f2`in_mine);

        printMyFreddies(f1, f3, 0);     // 1.7, 3.7;       1.7;  3.7;  3.7, 1.7      (modified)
        printYourFreddies(f1, f3, 0);   // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 (unmodified)

        // observe f2 is now solo in mine; in yours, it was just traversed
        printMyFreddies(f2, *0p, 0);    // 2.7; 2.7; ;

        // TODO: decide on appropriate ovservable outcome (is_listed?) and its itended semantics
        assert(f2.$links_mine.next.is_terminator == false);
        assert(f2.$links_mine.prev.is_terminator == false);
}

void test__remove_mid__fred_yours() {

        fred f1 = {1.7};
        fred f2 = {2.7};
        fred f3 = {3.7};

        insert_after(f1`in_mine, f2);
        insert_after(f2`in_mine, f3);

        insert_after(f1`in_yours, f2);
        insert_after(f2`in_yours, f3);

        printMyFreddies(f1, f3, 1);     // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 
        printYourFreddies(f1, f3, 1);   // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 

        remove(f2`in_yours);

        printMyFreddies(f1, f3, 0);     // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 (unmodified)
        printYourFreddies(f1, f3, 0);   // 1.7, 3.7;       1.7;  3.7;  3.7, 1.7      (modified)

        // observe f2 is now solo in yours; in mine, it was just traversed
        printYourFreddies(f2, *0p, 0);    // 2.7; 2.7; ;

        // TODO: decide on appropriate ovservable outcome (is_listed?) and its itended semantics
        assert(f2.$links_yours.next.is_terminator == false);
        assert(f2.$links_yours.prev.is_terminator == false);
}

void test__remove_mid__mary() {

        mary m1 = {1.7};
        mary m2 = {2.7};
        mary m3 = {3.7};

        insert_after(m1, m2);
        insert_after(m2, m3);

        printMariatheotokos(m1, m3, 1);     // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 

        remove(m2);

        printMariatheotokos(m1, m3, 0);     // 1.7, 3.7;  1.7;  3.7;  3.7, 1.7 (modified)

        // observe m2 is now solo
        printMariatheotokos(m2, *0p, 0);    // 2.7; 2.7; ;

        // TODO: decide on appropriate ovservable outcome (is_listed?) and its itended semantics
        assert(m2.$links.next.is_terminator == false);
        assert(m2.$links.prev.is_terminator == false);
}

////////////////////////////////////////////////////////////
//
// Section 4d.ii
//
// Test cases of remove, from first position of headless list
//
// Example of call-side user code
//
////////////////////////////////////////////////////////////

// TODO: validate headless semantic: remove of a neighbourless element is valid and no-op

void test__remove_at_first__fred_mine() {

        fred f1 = {1.7};
        fred f2 = {2.7};
        fred f3 = {3.7};

        insert_after(f1`in_mine, f2);
        insert_after(f2`in_mine, f3);

        insert_after(f1`in_yours, f2);
        insert_after(f2`in_yours, f3);

        printMyFreddies(f1, f3, 1);     // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 
        printYourFreddies(f1, f3, 1);   // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 

        remove(f1`in_mine);

        printMyFreddies(f2, f3, 0);     // 2.7, 3.7;       2.7;  3.7;  3.7, 2.7      (modified)
        printYourFreddies(f1, f3, 0);   // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 (unmodified)

        // observe f1 is now solo in mine; in yours, it was just traversed
        printMyFreddies(f1, *0p, 0);    // 1.7; 1.7; ;

        // TODO: decide on appropriate ovservable outcome (is_listed?) and its itended semantics
        assert(f1.$links_mine.next.is_terminator == false);
        assert(f1.$links_mine.prev.is_terminator == false);
}

void test__remove_at_first__fred_yours() {

        fred f1 = {1.7};
        fred f2 = {2.7};
        fred f3 = {3.7};

        insert_after(f1`in_mine, f2);
        insert_after(f2`in_mine, f3);

        insert_after(f1`in_yours, f2);
        insert_after(f2`in_yours, f3);

        printMyFreddies(f1, f3, 1);     // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 
        printYourFreddies(f1, f3, 1);   // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 

        remove(f1`in_yours);

        printMyFreddies(f1, f3, 0);     // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 (unmodified)
        printYourFreddies(f2, f3, 0);   // 2.7, 3.7;       2.7;  3.7;  3.7, 2.7      (modified)

        // observe f1 is now solo in yours; in mine, it was just traversed
        printYourFreddies(f1, *0p, 0);    // 1.7; 1.7; ;

        // TODO: decide on appropriate ovservable outcome (is_listed?) and its itended semantics
        assert(f1.$links_yours.next.is_terminator == false);
        assert(f1.$links_yours.prev.is_terminator == false);
}

void test__remove_at_first__mary() {

        mary m1 = {1.7};
        mary m2 = {2.7};
        mary m3 = {3.7};

        insert_after(m1, m2);
        insert_after(m2, m3);

        printMariatheotokos(m1, m3, 1);     // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 

        remove(m1);

        printMariatheotokos(m2, m3, 0);     // 2.7, 3.7;  2.7;  3.7;  3.7, 2.7 (modified)

        // observe m2 is now solo
        printMariatheotokos(m1, *0p, 0);    // 1.7; 1.7; ;

        // TODO: decide on appropriate ovservable outcome (is_listed?) and its itended semantics
        assert(m1.$links.next.is_terminator == false);
        assert(m1.$links.prev.is_terminator == false);
}

////////////////////////////////////////////////////////////
//
// Section 4d.iii
//
// Test cases of remove, from last position of headless list
//
// Example of call-side user code
//
////////////////////////////////////////////////////////////

void test__remove_at_last__fred_mine() {

        fred f1 = {1.7};
        fred f2 = {2.7};
        fred f3 = {3.7};

        insert_after(f1`in_mine, f2);
        insert_after(f2`in_mine, f3);

        insert_after(f1`in_yours, f2);
        insert_after(f2`in_yours, f3);

        printMyFreddies(f1, f3, 1);     // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 
        printYourFreddies(f1, f3, 1);   // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 

        remove(f3`in_mine);

        printMyFreddies(f1, f2, 0);     // 1.7, 2.7;       1.7;  2.7;  2.7, 1.7      (modified)
        printYourFreddies(f1, f3, 0);   // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 (unmodified)

        // observe f3 is now solo in mine; in yours, it was just traversed
        printMyFreddies(f3, *0p, 0);    // 3.7; 3.7; ;

        // TODO: decide on appropriate ovservable outcome (is_listed?) and its itended semantics
        assert(f3.$links_mine.next.is_terminator == false);
        assert(f3.$links_mine.prev.is_terminator == false);
}

void test__remove_at_last__fred_yours() {

        fred f1 = {1.7};
        fred f2 = {2.7};
        fred f3 = {3.7};

        insert_after(f1`in_mine, f2);
        insert_after(f2`in_mine, f3);

        insert_after(f1`in_yours, f2);
        insert_after(f2`in_yours, f3);

        printMyFreddies(f1, f3, 1);     // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 
        printYourFreddies(f1, f3, 1);   // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 

        remove(f3`in_yours);

        printMyFreddies(f1, f3, 0);     // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 (unmodified)
        printYourFreddies(f1, f2, 0);   // 1.7, 2.7;       1.7;  2.7;  2.7, 1.7      (modified)

        // observe f3 is now solo in yours; in mine, it was just traversed
        printYourFreddies(f3, *0p, 0);    // 3.7; 3.7; ;

        // TODO: decide on appropriate ovservable outcome (is_listed?) and its itended semantics
        assert(f3.$links_yours.next.is_terminator == false);
        assert(f3.$links_yours.prev.is_terminator == false);
}

void test__remove_at_last__mary() {

        mary m1 = {1.7};
        mary m2 = {2.7};
        mary m3 = {3.7};

        insert_after(m1, m2);
        insert_after(m2, m3);

        printMariatheotokos(m1, m3, 1);     // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 

        remove(m3);

        printMariatheotokos(m1, m2, 0);     // 1.7, 2.7;  1.7;  2.7;  2.7, 1.7 (modified)

        // observe m3 is now solo
        printMariatheotokos(m3, *0p, 0);    // 3.7; 3.7; ;

        // TODO: decide on appropriate ovservable outcome (is_listed?) and its itended semantics
        assert(m1.$links.next.is_terminator == false);
        assert(m1.$links.prev.is_terminator == false);
}

////////////////////////////////////////////////////////////
//
// Section 4e.i
//
// Test cases of remove, from first position of headed list
//
// Example of call-side user code
//
////////////////////////////////////////////////////////////

void test__remove_at_head__fred_mine() {

        fred f1 = {1.7};
        fred f2 = {2.7};
        fred f3 = {3.7};

        dlist(fred_in_mine, fred) flm;
        insert_last(flm, f1);
        insert_last(flm, f2);
        insert_last(flm, f3);

        dlist(fred_in_yours, fred) fly;
        insert_last(fly, f1);
        insert_last(fly, f2);
        insert_last(fly, f3);

        printMyFreddies(flm`first, flm`last, 1);     // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 
        printYourFreddies(fly`first, fly`last, 1);   // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 

        remove(f1`in_mine);

        printMyFreddies(flm`first, flm`last, 0);     // 2.7, 3.7;       2.7;  3.7;  3.7, 2.7      (modified)
        printYourFreddies(fly`first, fly`last, 0);   // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 (unmodified)

        // observe f1 is now solo in mine; in yours, it was just traversed
        printMyFreddies(f1, *0p, 0);    // 1.7; 1.7; ;

        // TODO: decide on appropriate ovservable outcome (is_listed?) and its itended semantics
        assert(f1.$links_mine.next.is_terminator == false);
        assert(f1.$links_mine.prev.is_terminator == false);
}

void test__remove_at_head__fred_yours() {

        fred f1 = {1.7};
        fred f2 = {2.7};
        fred f3 = {3.7};

        dlist(fred_in_mine, fred) flm;
        insert_last(flm, f1);
        insert_last(flm, f2);
        insert_last(flm, f3);

        dlist(fred_in_yours, fred) fly;
        insert_last(fly, f1);
        insert_last(fly, f2);
        insert_last(fly, f3);

        printMyFreddies(flm`first, flm`last, 1);     // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 
        printYourFreddies(fly`first, fly`last, 1);   // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 

        remove(f1`in_yours);

        printMyFreddies(flm`first, flm`last, 0);     // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 (unmodified)
        printYourFreddies(fly`first, fly`last, 0);   // 2.7, 3.7;       2.7;  3.7;  3.7, 2.7      (modified)

        // observe f1 is now solo in yours; in mine, it was just traversed
        printYourFreddies(f1, *0p, 0);    // 1.7; 1.7; ;

        // TODO: decide on appropriate ovservable outcome (is_listed?) and its itended semantics
        assert(f1.$links_yours.next.is_terminator == false);
        assert(f1.$links_yours.prev.is_terminator == false);
}

void test__remove_at_head__mary() {

        mary m1 = {1.7};
        mary m2 = {2.7};
        mary m3 = {3.7};

        dlist(mary, mary) ml;
        insert_last(ml, m1);
        insert_last(ml, m2);
        insert_last(ml, m3);

        printMariatheotokos(ml`first, ml`last, 1);     // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 

        remove(m1);

        printMariatheotokos(ml`first, ml`last, 0);     // 2.7, 3.7;       2.7;  3.7;  3.7, 2.7      (modified)

        // observe m1 is now solo
        printMariatheotokos(m1, *0p, 0);               // 1.7; 1.7; ;

        // TODO: decide on appropriate ovservable outcome (is_listed?) and its itended semantics
        assert(m1.$links.next.is_terminator == false);
        assert(m1.$links.prev.is_terminator == false);
}

////////////////////////////////////////////////////////////
//
// Section 4e.ii
//
// Test cases of remove, from last position of headed list
//
// Example of call-side user code
//
////////////////////////////////////////////////////////////

void test__remove_at_tail__fred_mine() {

        fred f1 = {1.7};
        fred f2 = {2.7};
        fred f3 = {3.7};

        dlist(fred_in_mine, fred) flm;
        insert_last(flm, f1);
        insert_last(flm, f2);
        insert_last(flm, f3);

        dlist(fred_in_yours, fred) fly;
        insert_last(fly, f1);
        insert_last(fly, f2);
        insert_last(fly, f3);

        printMyFreddies(flm`first, flm`last, 1);     // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 
        printYourFreddies(fly`first, fly`last, 1);   // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 

        remove(f3`in_mine);

        printMyFreddies(flm`first, flm`last, 0);     // 1.7, 2.7;       1.7;  2.7;  2.7, 1.7      (modified)
        printYourFreddies(fly`first, fly`last, 0);   // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 (unmodified)

        // observe f3 is now solo in mine; in yours, it was just traversed
        printMyFreddies(f3, *0p, 0);    // 3.7; 3.7; ;

        // TODO: decide on appropriate ovservable outcome (is_listed?) and its itended semantics
        assert(f3.$links_mine.next.is_terminator == false);
        assert(f3.$links_mine.prev.is_terminator == false);
}

void test__remove_at_tail__fred_yours() {

        fred f1 = {1.7};
        fred f2 = {2.7};
        fred f3 = {3.7};

        dlist(fred_in_mine, fred) flm;
        insert_last(flm, f1);
        insert_last(flm, f2);
        insert_last(flm, f3);

        dlist(fred_in_yours, fred) fly;
        insert_last(fly, f1);
        insert_last(fly, f2);
        insert_last(fly, f3);

        printMyFreddies(flm`first, flm`last, 1);     // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 
        printYourFreddies(fly`first, fly`last, 1);   // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 

        remove(f3`in_yours);

        printMyFreddies(flm`first, flm`last, 0);     // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 (unmodified)
        printYourFreddies(fly`first, fly`last, 0);   // 1.7, 2.7;       1.7;  2.7;  2.7, 1.7      (modified)

        // observe f3 is now solo in yours; in mine, it was just traversed
        printYourFreddies(f3, *0p, 0);               // 3.7; 3.7; ;

        // TODO: decide on appropriate ovservable outcome (is_listed?) and its itended semantics
        assert(f3.$links_yours.next.is_terminator == false);
        assert(f3.$links_yours.prev.is_terminator == false);
}

void test__remove_at_tail__mary() {

        mary m1 = {1.7};
        mary m2 = {2.7};
        mary m3 = {3.7};

        dlist(mary, mary) ml;
        insert_last(ml, m1);
        insert_last(ml, m2);
        insert_last(ml, m3);

        printMariatheotokos(ml`first, ml`last, 1);     // 1.7, 2.7, 3.7;  1.7;  3.7;  3.7, 2.7, 1.7 

        remove(m3);

        printMariatheotokos(ml`first, ml`last, 0);     // 1.7, 2.7;       1.7;  2.7;  2.7, 1.7      (modified)

        // observe m3 is now solo
        printMariatheotokos(m3, *0p, 0);               //3.7; 3.7; ;

        // TODO: decide on appropriate ovservable outcome (is_listed?) and its itended semantics
        assert(m3.$links.next.is_terminator == false);
        assert(m3.$links.prev.is_terminator == false);
}

////////////////////////////////////////////////////////////
//
// Section 4e.iii
//
// Test cases of remove, of sole element of headed list
//
// Example of call-side user code
//
////////////////////////////////////////////////////////////

void test__remove_of_sole__fred_mine() {

        fred f = {0.7};

        dlist(fred_in_mine, fred) flm;
        insert_last(flm, f);

        dlist(fred_in_yours, fred) fly;
        insert_last(fly, f);

        printMyFreddies(flm`first, flm`last, 1);     // 0.7; 0.7; 0.7; 0.7
        printYourFreddies(fly`first, fly`last, 1);   // 0.7; 0.7; 0.7; 0.7

        remove(f`in_mine);

        assert(& flm`first == 0p);
        assert(& flm`last  == 0p);

        printYourFreddies(fly`first, fly`last, 0);   // 0.7; 0.7; 0.7; 0.7 (unmodified)

        // observe f is solo in mine (now unlisted); in yours, it was just traversed
        printMyFreddies(f, *0p, 0);    // 0.7; 0.7; ;

        // TODO: decide on appropriate ovservable outcome (is_listed?) and its itended semantics
        assert(f.$links_mine.next.is_terminator == false);
        assert(f.$links_mine.prev.is_terminator == false);

        insert_last(flm, f);
        printMyFreddies(flm`first, flm`last, 0);     // 0.7; 0.7; 0.7; 0.7
}

void test__remove_of_sole__fred_yours() {

        fred f = {0.7};

        dlist(fred_in_mine, fred) flm;
        insert_last(flm, f);

        dlist(fred_in_yours, fred) fly;
        insert_last(fly, f);

        printMyFreddies(flm`first, flm`last, 1);     // 0.7; 0.7; 0.7; 0.7
        printYourFreddies(fly`first, fly`last, 1);   // 0.7; 0.7; 0.7; 0.7

        remove(f`in_yours);

        assert(& fly`first == 0p);
        assert(& fly`last  == 0p);

        printYourFreddies(flm`first, flm`last, 0);   // 0.7; 0.7; 0.7; 0.7 (unmodified)

        // observe f is solo in yours (now unlisted); in mine, it was just traversed
        printYourFreddies(f, *0p, 0);    // 0.7; 0.7; ;

        // TODO: decide on appropriate ovservable outcome (is_listed?) and its itended semantics
        assert(f.$links_yours.next.is_terminator == false);
        assert(f.$links_yours.prev.is_terminator == false);

        insert_last(fly, f);
        printYourFreddies(fly`first, fly`last, 0);     // 0.7; 0.7; 0.7; 0.7
}

void test__remove_of_sole__mary() {

        mary m = {0.7};

        dlist(mary, mary) ml;
        insert_last(ml, m);

        printMariatheotokos(ml`first, ml`last, 1);     // 0.7; 0.7; 0.7; 0.7

        remove(m);

        assert(& ml`first == 0p);
        assert(& ml`last  == 0p);

        // observe f is solo in mine (now unlisted); in yours, it was just traversed
        printMariatheotokos(m, *0p, 0);    // 0.7; 0.7; ;

        // TODO: decide on appropriate ovservable outcome (is_listed?) and its itended semantics
        assert(m.$links.next.is_terminator == false);
        assert(m.$links.prev.is_terminator == false);

        insert_last(ml, m);
        printMariatheotokos(ml`first, ml`last, 0);     // 0.7; 0.7; 0.7; 0.7
}

////////////////////////////////////////////////////////////
//
// Section 5
//
// Simple driver with the inter-scario printing
//
////////////////////////////////////////////////////////////

int main() {

        sout | "~~~~~~~~~~~~~~~~~ Headless List Tests - insert_after ~~~~~~~~~~~~~~~~";
        sout | "";

        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        sout | "Test 1-i:  Modifying Freds on MINE ";
        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        test__insertafter_singleton_on_singleton__fred_mine();

        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        sout | "Test 2-i.  Modifying Freds on YOURS";
        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        test__insertafter_singleton_on_singleton__fred_yours();

        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        sout | "Test 3-i.  Modifying Maries";
        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        test__insertafter_singleton_on_singleton__mary();

        sout | "";
        sout | "~~~~~~~~~~~~~~~~ Headless List Tests - insert_before ~~~~~~~~~~~~~~~~";
        sout | "";

        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        sout | "Test 1-ii:  Modifying Freds on MINE ";
        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        test__insertbefore_singleton_on_singleton__fred_mine();

        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        sout | "Test 2-ii.  Modifying Freds on YOURS";
        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        test__insertbefore_singleton_on_singleton__fred_yours();

        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        sout | "Test 3-ii.  Modifying Maries";
        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        test__insertbefore_singleton_on_singleton__mary();

        sout | "";
        sout | "~~~~~~~~~~~~~~~~~ Headed List Tests - insert_first ~~~~~~~~~~~~~~~~~~";
        sout | "";

        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        sout | "Test 4-i:  Modifying Freds on MINE ";
        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        test__insertfirst_two_on_empty__fred_mine();

        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        sout | "Test 5-i:  Modifying Freds on YOURS ";
        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        test__insertfirst_two_on_empty__fred_yours();

        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        sout | "Test 6-i.  Modifying Maries";
        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        test__insertfirst_two_on_empty__mary();

        sout | "";
        sout | "~~~~~~~~~~~~~~~~~ Headed List Tests - insert_last ~~~~~~~~~~~~~~~~~~~";
        sout | "";

        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        sout | "Test 4-ii:  Modifying Freds on MINE ";
        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        test__insertlast_two_on_empty__fred_mine();

        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        sout | "Test 5-ii:  Modifying Freds on YOURS ";
        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        test__insertlast_two_on_empty__fred_yours();

        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        sout | "Test 6-ii.  Modifying Maries";
        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        test__insertlast_two_on_empty__mary();

        sout | "";
        sout | "~~~~~~~~~~~ Element ops on Headed List Tests: after, last ~~~~~~~~~~~";
        sout | "";

        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        sout | "Test 7-i.  Modifying Freds on MINE";
        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        test__insertafter_after_last__fred_mine();

        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        sout | "Test 8-i.  Modifying Freds on YOURS";
        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        test__insertafter_after_last__fred_yours();

        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~";
        sout | "Test 9-i.  Modifying Maries";
        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~";
        test__insertafter_after_last__mary();

        sout | "";
        sout | "~~~~~~~~~~ Element ops on Headed List Tests: before, first ~~~~~~~~~~";
        sout | "";

        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        sout | "Test 7-ii.  Modifying Freds on MINE";
        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        test__insertbefore_before_first__fred_mine();

        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        sout | "Test 8-ii.  Modifying Freds on YOURS";
        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        test__insertbefore_before_first__fred_yours();

        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        sout | "Test 9-ii.  Modifying Maries";
        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        test__insertbefore_before_first__mary();

        sout | "";
        sout | "~~~~~~~~~~ Element removal tests on Headless List: mid ~~~~~~~~~~";
        sout | "";

        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        sout | "Test 10-i.  Modifying Freds on MINE";
        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        test__remove_mid__fred_mine();

        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        sout | "Test 11-i.  Modifying Freds on YOURS";
        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        test__remove_mid__fred_yours();

        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        sout | "Test 12-i.  Modifying Maries";
        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        test__remove_mid__mary();

        sout | "";
        sout | "~~~~~~~~~~ Element removal tests on Headless List: at first ~~~~~~~~~~";
        sout | "";

        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        sout | "Test 10-ii.  Modifying Freds on MINE";
        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        test__remove_at_first__fred_mine();

        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        sout | "Test 11-ii.  Modifying Freds on YOURS";
        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        test__remove_at_first__fred_yours();

        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        sout | "Test 12-ii.  Modifying Maries";
        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        test__remove_at_first__mary();

        sout | "";
        sout | "~~~~~~~~~~ Element removal tests on Headless List: at last ~~~~~~~~~~";
        sout | "";

        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        sout | "Test 10-iii.  Modifying Freds on MINE";
        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        test__remove_at_last__fred_mine();

        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        sout | "Test 11-iii.  Modifying Freds on YOURS";
        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        test__remove_at_last__fred_yours();

        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        sout | "Test 12-iii.  Modifying Maries";
        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        test__remove_at_last__mary();

        sout | "";
        sout | "~~~~~~~~~~ Element removal tests on Headed List: at first ~~~~~~~~~~";
        sout | "";

        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        sout | "Test 13-i.  Modifying Freds on MINE";
        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        test__remove_at_head__fred_mine();

        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        sout | "Test 14-i.  Modifying Freds on YOURS";
        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        test__remove_at_head__fred_yours();

        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        sout | "Test 15-i.  Modifying Maries";
        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        test__remove_at_head__mary();

        sout | "";
        sout | "~~~~~~~~~~ Element removal tests on Headed List: at last ~~~~~~~~~~";
        sout | "";

        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        sout | "Test 13-ii.  Modifying Freds on MINE";
        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        test__remove_at_tail__fred_mine();

        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        sout | "Test 14-ii.  Modifying Freds on YOURS";
        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        test__remove_at_tail__fred_yours();

        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        sout | "Test 15-ii.  Modifying Maries";
        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        test__remove_at_tail__mary();

        sout | "";
        sout | "~~~~~~~~~~ Element removal tests on Headed List: of sole ~~~~~~~~~~";
        sout | "";

        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        sout | "Test 13-iii.  Modifying Freds on MINE";
        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        test__remove_of_sole__fred_mine();

        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        sout | "Test 14-iii.  Modifying Freds on YOURS";
        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        test__remove_of_sole__fred_yours();

        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        sout | "Test 15-iii.  Modifying Maries";
        sout | "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
        test__remove_of_sole__mary();

        return 0;
}