Calc
Inductive()
Lemma
NewType()
Proof
QExists()
QForAll()
Struct()
axiom()
cond()
define()
prove()
search()
simp()
forget()
Defn
LemmaError
beta_conv()
consider()
define_fix()
defns
einstan()
forget2()
fresh_const()
herb()
induct_inductive()
instan()
instan2()
is_defined()
is_proof()
skolem()
“Forget” a term using existentials. This is existential introduction. This could be derived from forget2
ts (Iterable[ExprRef])
pf (Proof)