import Lean.Meta open Lean open Lean.Meta axiom simple : forall {p q : Prop}, p → q → p def print (msg : MessageData) : MetaM Unit := do trace[Meta.Tactic] msg def tst1 : MetaM Unit := do let cinfo ← getConstInfo `simple let mvar ← mkFreshExprSyntheticOpaqueMVar cinfo.type let mvarId := mvar.mvarId! let (_, mvarId) ← mvarId.introN 4 mvarId.assumption let result ← instantiateMVars mvar print result set_option trace.Meta.Tactic true /-- info: [Meta.Tactic] fun {p q} a a_1 => a -/ #guard_msgs in #eval tst1