Calc
Inductive()
Lemma
NewType()
Proof
QExists()
QForAll()
Struct()
axiom()
cond()
define()
prove()
search()
simp()
None_()
Option()
Some()
get()
is_option()
Get the value of an Option, or a default value if it is None_ >>> get(Some(42), 0) If(is(Some, Some(42)), val(Some(42)), 0)
x (DatatypeRef)
default (ExprRef)
ExprRef