function run_tests() {

console.assert(abs(0) == 0, "abs(0) == 0");

console.assert(abs(1) == 1, "abs(1) == 1");

console.assert(abs(-1) == 1, "abs(-1) == 1");

console.assert(1/0 == 1/abs(-0), "1/0 == 1/abs(-0)");

console.assert(1/-0 != 1/abs(-0), "1/-0 != 1/abs(-0)");

}

run_tests();