Files
mercury/tests/term/pl4_5_2.m
Zoltan Somogyi 9cacd33f47 Remove "is" as a synonym for "=", step 1.
This first step deals with the consequences of such removal.
The removal itself will happen in stage 2. That step will
add "is" to the prolog module in the library.

compiler/add_pred.m:
    Prepare for "is" being in the prolog module.

compiler/options.m:
    Add a way to test whether the change to add_pred.m is in the
    installed compiler.

tests/accumulator/base.m:
tests/accumulator/call_in_base.m:
tests/accumulator/chain.m:
tests/accumulator/commutative.m:
tests/accumulator/construct_test.m:
tests/accumulator/dcg.m:
tests/accumulator/deconstruct_test.m:
tests/accumulator/disj.m:
tests/accumulator/func.m:
tests/accumulator/heuristic.m:
tests/accumulator/highorder.m:
tests/accumulator/identity.m:
tests/accumulator/inter.m:
tests/accumulator/nonrec.m:
tests/accumulator/out_to_in.m:
tests/accumulator/qsort.m:
tests/accumulator/simple.m:
tests/accumulator/split.m:
tests/accumulator/swap.m:
tests/benchmarks/cqueens.m:
tests/benchmarks/crypt.m:
tests/benchmarks/deriv.m:
tests/benchmarks/deriv2.m:
tests/benchmarks/nrev.m:
tests/benchmarks/poly.m:
tests/benchmarks/primes.m:
tests/benchmarks/qsort.m:
tests/benchmarks/query.m:
tests/benchmarks/tak.m:
tests/debugger/interactive.m:
tests/declarative_debugger/Mercury.options:
tests/declarative_debugger/io_read_bug.m:
tests/declarative_debugger/queens.exp:
tests/declarative_debugger/queens.m:
tests/dppd/imperative_solve_impl.m:
tests/dppd/map_impl.m:
tests/dppd/max_length_impl.m:
tests/dppd/sum.m:
tests/dppd/upto_sum_impl.m:
tests/par_conj/dep_par_21.m:
tests/tabling/seq.m:
tests/term/dds3_14.m:
tests/term/mmatrix.m:
tests/term/money.m:
tests/term/occur.m:
tests/term/pl4_5_2.m:
tests/term/queens.m:
tests/typeclasses/inference_test.m:
tests/typeclasses/inference_test_2.m:
tests/valid/lazy_list.m:
tests/warnings/duplicate_const.m:
    Replace calls to "is" with unifications. In many places,
    bring programming style up to date.
2020-08-21 10:42:37 +10:00

34 lines
642 B
Mathematica

%---------------------------------------------------------------------------%
% vim: ts=4 sw=4 et ft=mercury
%---------------------------------------------------------------------------%
:- module pl4_5_2.
:- interface.
:- type expr
---> expr + expr
; num(int).
:- pred s(expr::in, expr::out) is nondet.
:- implementation.
:- import_module int.
:- import_module prolog.
s(A + (B + C), D) :-
s((A + B) + C, D).
s(A + B, C) :-
s(B + A, C).
s(X + num(0), X).
s(X + Y, Z) :-
s(X, A),
s(Y, B),
s(A + B, Z).
s(A + B, C) :-
A = num(Anum),
B = num(Bnum),
Cnum = Anum + Bnum,
C = num(Cnum).