1:      1  1 CALL pred interactive.main/2-0 (cc_multi) interactive.m:27
mdb> echo on
Command echo enabled.
mdb> step 4
       5:      3  2 CALL pred interactive.queen/2-0 (nondet) interactive.m:48 (interactive.m:28)
mdb> query interactive list
?- append(X, Y, ['a', 'b', 'c']).
<stdin>:001: Inferred :- pred query(mdb_query.inputs, list.list(character),
<stdin>:001:   list.list(character)).
X = [], Y = ['a', 'b', 'c'], true ;
X = ['a'], Y = ['b', 'c'], true ;
X = ['a', 'b'], Y = ['c'], true ;
X = ['a', 'b', 'c'], Y = [], true ;
fail.
No (more) solutions.
?- qperm([1,2,3], List).
<stdin>:001: Inferred :- pred query(mdb_query.inputs, list.list(int)).
List = [1, 2, 3], true ;
List = [1, 3, 2], true ;
List = [2, 1, 3], true ;
List = [2, 3, 1], true ;
List = [3, 1, 2], true ;
List = [3, 2, 1], true ;
fail.
No (more) solutions.
?- qperm([1,2,3], List), List = [2 | _].
<stdin>:001: Inferred :- pred query(mdb_query.inputs, list.list(int)).
List = [2, 1, 3], true ;
List = [2, 3, 1], true ;
fail.
No (more) solutions.
?- qperm([1,2,3], List), List = [4 | _].
<stdin>:001: Inferred :- pred query(mdb_query.inputs, list.list(int)).
fail.
No (more) solutions.
?- qperm([1,2,"foo"], List).
<stdin>:001: In clause for predicate `query'/2:
<stdin>:001:   in argument 1 of call to predicate `qperm'/2:
<stdin>:001:   in list element #2:
<stdin>:001:   type error in unification of argument
<stdin>:001:   and constant `"foo"'.
<stdin>:001:   argument has type `int',
<stdin>:001:   constant `"foo"' has type `string'.
For more information, recompile with `-E'.
Compilation error(s) occurred.
?- qperm(List, [1]).
<stdin>:001: In clause for `query(in, out)':
<stdin>:001:   in argument 1 of call to predicate `interactive.qperm'/2:
<stdin>:001:   mode error: variable `List' has instantiatedness `free',
<stdin>:001:   expected instantiatedness was `ground'.
<stdin>:001: Inferred :- pred query(mdb_query.inputs, list.list(int)).
Compilation error(s) occurred.
?- queen(Data, Solution).
<stdin>:001: Inferred :- pred query(mdb_query.inputs, list.list(int)).
Solution = [1, 3, 5, 2, 4], true ;
Solution = [1, 4, 2, 5, 3], true ;
Solution = [2, 4, 1, 3, 5], true ;
Solution = [2, 5, 3, 1, 4], true ;
Solution = [3, 1, 4, 2, 5], true ;
Solution = [3, 5, 2, 4, 1], true ;
Solution = [4, 1, 3, 5, 2], true ;
Solution = [4, 2, 5, 3, 1], true ;
Solution = [5, 2, 4, 1, 3], true ;
Solution = [5, 3, 1, 4, 2], true ;
fail.
No (more) solutions.
?- det_take(10, Data, Start).
<stdin>:001: Inferred :- pred query(mdb_query.inputs, list.list(int)).
*** caught exception: software_error("list.m: predicate `list.det_take\'/3: Unexpected: index out of range")
No (more) solutions.
?- quit.

mdb> cc_query interactive list
?- append(X, Y, ['a', 'b', 'c']).
<stdin>:001: Inferred :- pred query(mdb_query.inputs, list.list(character),
<stdin>:001:   list.list(character)).
X = [], Y = ['a', 'b', 'c'], true.
?- qperm([1,2,3], List).
<stdin>:001: Inferred :- pred query(mdb_query.inputs, list.list(int)).
List = [1, 2, 3], true.
?- qperm([1,2,3], List), List = [2 | _].
<stdin>:001: Inferred :- pred query(mdb_query.inputs, list.list(int)).
List = [2, 1, 3], true.
?- qperm([1,2,3], List), List = [4 | _].
<stdin>:001: Inferred :- pred query(mdb_query.inputs, list.list(int)).
No solution.
?- queen(Data, Solution).
<stdin>:001: Inferred :- pred query(mdb_query.inputs, list.list(int)).
Solution = [1, 3, 5, 2, 4], true.
?- det_take(10, Data, Start).
<stdin>:001: Inferred :- pred query(mdb_query.inputs, list.list(int)).
*** caught exception: software_error("list.m: predicate `list.det_take\'/3: Unexpected: index out of range")
?- quit.

mdb> io_query interactive list
run <-- main.
<stdin>:001: Inferred :- pred query(mdb_query.inputs, io.state, io.state).
[1, 3, 5, 2, 4]
run <-- if { append(X, Y, ['a', 'b', 'c']) } then print("X = "), print(X), print(", Y = "), print(Y), nl else print("No solution\n").
<stdin>:001: Inferred :- pred query(mdb_query.inputs, io.state, io.state).
X = [], Y = ['a', 'b', 'c']
run <-- if { qperm([1,2,3], List) } then print(List), nl else [].
<stdin>:001: Inferred :- pred query(mdb_query.inputs, io.state, io.state).
[1, 2, 3]
run <-- if { qperm([1,2,3], List), List = [2 | _] } then print(List), nl else { true }.
<stdin>:001: Inferred :- pred query(mdb_query.inputs, io.state, io.state).
[2, 1, 3]
run <-- if { qperm([1,2,3], List), List = [4 | _] } then print(List), nl else print("No solution, as expected."), io__nl.
<stdin>:001: Inferred :- pred query(mdb_query.inputs, io.state, io.state).
No solution, as expected.
run <-- if { queen(Data, Solution) } then print(Solution), nl else { true }.
<stdin>:001: Inferred :- pred query(mdb_query.inputs, io.state, io.state).
[1, 3, 5, 2, 4]
run <-- { det_take(10, Data, Start) }, print(Start), nl.
<stdin>:001: Inferred :- pred query(mdb_query.inputs, io.state, io.state).
*** caught exception: software_error("list.m: predicate `list.det_take\'/3: Unexpected: index out of range")
run <-- quit.

mdb> continue -n -S
[1, 3, 5, 2, 4]