47 lines
1.5 KiB
Text
47 lines
1.5 KiB
Text
/-
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Copyright (c) 2016 Microsoft Corporation. All rights reserved.
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Released under Apache 2.0 license as described in the file LICENSE.
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Authors: Leonardo de Moura
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-/
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prelude
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import init.meta.tactic init.function
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namespace tactic
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open expr
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private meta def relation_tactic (t : transparency) (op_for : environment → name → option name) (tac_name : string) : tactic unit :=
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do tgt ← target,
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env ← get_env,
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r ← return $ get_app_fn tgt,
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match (op_for env (const_name r)) with
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| (some refl) := mk_const refl >>= apply_core t tt ff tt
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| none := fail $ tac_name ++ " tactic failed, target is not a relation application with the expected property."
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end
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meta def reflexivity_core (t : transparency) : tactic unit :=
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relation_tactic t environment.refl_for "reflexivity"
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meta def reflexivity : tactic unit :=
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reflexivity_core semireducible
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meta def symmetry : tactic unit :=
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relation_tactic semireducible environment.symm_for "symmetry"
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meta def transitivity : tactic unit :=
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relation_tactic semireducible environment.trans_for "transitivity"
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meta def relation_lhs_rhs : expr → tactic (name × expr × expr) :=
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λ e, do
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(const c _) ← return e^.get_app_fn,
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env ← get_env,
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(some (arity, lhs_pos, rhs_pos)) ← return $ env^.relation_info c,
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args ← return $ get_app_args e,
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guard (args^.length = arity),
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(some lhs) ← return $ args^.nth lhs_pos,
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(some rhs) ← return $ args^.nth rhs_pos,
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return (c, lhs, rhs)
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meta def target_lhs_rhs : tactic (name × expr × expr) :=
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target >>= relation_lhs_rhs
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end tactic
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