Calc
Inductive()
Lemma
NewType()
Proof
QExists()
QForAll()
Struct()
axiom()
cond()
define()
prove()
search()
simp()
None_()
Option()
Some()
get()
is_option()
Check if a value is an Option >>> is_option(Some(42)) True >>> is_option(42) False
x (DatatypeRef)
bool