22 lines
768 B
Text
22 lines
768 B
Text
open tactic
|
|
|
|
example (a b : nat) : decidable (a = b) :=
|
|
by do t ← mk_app "decidable_eq" [expr.const "nat" []],
|
|
/- We had to mark that `i` is an expr because of a limitation of the current elaborator.
|
|
When we write (i a b), the current elaborator only considers the coercion expr.app to function class
|
|
if the type of `i` is known at preprocessing time. This limitation will be removed in the new
|
|
elaborator. -/
|
|
i : expr ← mk_instance t,
|
|
a ← get_local "a",
|
|
b ← get_local "b",
|
|
trace i,
|
|
exact (i a b)
|
|
|
|
example (a b : nat) : decidable (a = b) :=
|
|
by do t ← target,
|
|
i ← mk_instance t,
|
|
trace i,
|
|
exact i
|
|
|
|
example (a b : nat) : decidable (a = b) :=
|
|
by target >>= mk_instance >>= exact
|