def test_define_procedure(context):
program = "(begin (define (square x) (* x x)) (square 10))"
assert interpret(program, context) == 100
def test_evaluate_set():
assert interpret("(begin (define x 2) (set! x 3) x)") == 3
def test_evaluate_define():
assert interpret("(begin (define x 2) x)") == 2
def test_evaluate_if_false():
assert interpret("(if 0 2 3)") == 3
def test_evaluate_if_true():
assert interpret("(if 1 2 3)") == 2
def test_evaluate_constant_literal():
assert interpret("12") == 12
