open bool nat

-- set_option trace.compiler.code_gen true

attribute [reducible]
definition foo (b : bool) : Type :=
cond b nat (nat → nat)

definition bla (b : bool) : foo b → nat :=
bool.cases_on b (λ f, f 100) (λ n, n)

definition of_dec (p : Prop) [h : decidable p] : bool :=
decidable.cases_on h (λ h, ff) (λ h, tt)

definition boo (n : nat) := bla (of_dec (n > 10))

definition x : nat := 20

definition tst (b : bool) (a : nat) : foo b :=
bool.cases_on b (λ n : nat, n * a) a

#reduce bla ff (λ n : nat, n+10)
#reduce bla tt x
#reduce boo 11 x
#reduce boo 9 (λ n : nat, n+20)
#reduce tst ff 4 10
#reduce tst tt 3
#print "---------"
#eval bla ff (λ n : nat, n+10)
#eval bla tt x
#eval boo 11 x
#eval boo 9 (λ n : nat, n+20)
#eval tst ff 4 10
#eval tst tt 3