anthem/tests/TestCompletion.cpp

#include <catch.hpp>

#include <sstream>

#include <anthem/AST.h>
#include <anthem/Context.h>
#include <anthem/Translation.h>

////////////////////////////////////////////////////////////////////////////////////////////////////

TEST_CASE("[completion] Rules are completed", "[completion]")
{
	std::stringstream input;
	std::stringstream output;
	std::stringstream errors;

	anthem::output::Logger logger(output, errors);
	anthem::Context context(std::move(logger));
	context.performSimplification = true;
	context.performCompletion = true;

	SECTION("predicate in single rule head")
	{
		input << "p :- q.";
		anthem::translate("input", input, context);

		CHECK(output.str() ==
			"(p <-> q)\n"
			"not q\n");
	}

	SECTION("predicate in multiple rule heads")
	{
		input <<
			"p :- q.\n"
			"p :- r.\n"
			"p :- s.";
		anthem::translate("input", input, context);

		CHECK(output.str() ==
			"(p <-> (q or r or s))\n"
			"not q\n"
			"not r\n"
			"not s\n");
	}

	SECTION("multiple predicates are correctly separated")
	{
		input <<
			"p :- s.\n"
			"q :- t.\n"
			"p :- q.\n"
			"r :- t.\n"
			"q :- r.";
		anthem::translate("input", input, context);

		CHECK(output.str() ==
			"(p <-> (s or q))\n"
			"(q <-> (t or r))\n"
			"(r <-> t)\n"
			"not s\n"
			"not t\n");
	}

	SECTION("integrity constraints")
	{
		input <<
			":- q.\n"
			":- r(5).\n"
			":- s(N).\n"
			"#false :- t.\n"
			"#false :- u(5).";
		anthem::translate("input", input, context);

		CHECK(output.str() ==
			"not q\n"
			"forall V1 not r(V1)\n"
			"forall V2 not s(V2)\n"
			"not t\n"
			"forall V3 not u(V3)\n"
			"not q\n"
			"not r(5)\n"
			"forall U1 not s(U1)\n"
			"not t\n"
			"not u(5)\n");
	}

	SECTION("Booleans")
	{
		input <<
			"#true :- #true.\n"
			"#true :- #false.\n"
			"#false :- #true.\n"
			"#false :- #false.\n";
		anthem::translate("input", input, context);

		CHECK(output.str() ==
			"not #true\n"
			"not #false\n");
	}

	SECTION("facts")
	{
		input <<
			"q.\n"
			"r.\n"
			"s :- #true.\n"
			"t :- #true.";
		anthem::translate("input", input, context);

		CHECK(output.str() ==
			"q\n"
			"r\n"
			"s\n"
			"t\n");
	}

	SECTION("nested arguments")
	{
		input <<
			"f(f(f(f(f(X))))) :- f(X).\n"
			"f(1..5).";
		anthem::translate("input", input, context);

		CHECK(output.str() ==
			"forall V1 (f(V1) <-> (exists U1 (V1 = f(f(f(f(U1)))) and f(U1)) or V1 in (1..5)))\n");
	}

	SECTION("useless implications")
	{
		input <<
			"#true :- p, q(N), t(1, 2).\n"
			"#true.\n"
			"v :- #false.";
		anthem::translate("input", input, context);

		CHECK(output.str() ==
			"not p\n"
			"forall V1 not q(V1)\n"
			"forall V2, V3 not t(V2, V3)\n"
			"not v\n");
	}

	SECTION("Schur number example")
	{
		input <<
			"{in(1..n, 1..r)}.\n"
			"covered(I) :- in(I, S).\n"
			":- I = 1..n, not covered(I).\n"
			":- in(I, S), in(J, S), in(I + J, S).";
		anthem::translate("input", input, context);

		CHECK(output.str() ==
			"forall V1 (covered(V1) <-> exists U1 in(V1, U1))\n"
			"forall V2, V3 (in(V2, V3) -> (V2 in (1..n) and V3 in (1..r)))\n"
			"forall U2 (U2 in (1..n) -> covered(U2))\n"
			"forall U3, U4, U5 (not in(U3, U4) or not in(U5, U4) or not exists X1 (X1 in (U3 + U5) and in(X1, U4)))\n");
	}

	SECTION("binary operations with multiple variables")
	{
		input << "a(X, Y) :- b(c(X + Y), d(1 + Y)).";
		anthem::translate("input", input, context);

		CHECK(output.str() ==
			"forall V1, V2 (a(V1, V2) <-> b(c((V1 + V2)), d((1 + V2))))\n"
			"forall V3, V4 not b(V3, V4)\n");
	}

	SECTION("predicate with more than one argument")
	{
		input << "p(X, Y, Z).";
		anthem::translate("input", input, context);

		// TODO: simplify further
		CHECK(output.str() ==
			"forall V1, V2, V3 (p(V1, V2, V3) <-> #true)\n");
	}

	SECTION("negated comparisons")
	{
		input << ":- color(V, C1), color(V, C2), C1 != C2.";
		anthem::translate("input", input, context);

		CHECK(output.str() == "forall V1, V2 not color(V1, V2)\nforall U1, U2, U3 (not color(U1, U2) or not color(U1, U3) or U2 = U3)\n");
	}

	SECTION("absolute value operation")
	{
		input << "adj(X, Y) :- X = 1..n, Y = 1..n, |X - Y| = 1.";
		anthem::translate("input", input, context);

		CHECK(output.str() == "forall V1, V2 (adj(V1, V2) <-> (V1 in (1..n) and V2 in (1..n) and |V1 - V2| = 1))\n");
	}
}