diff options
| author |  Gaëtan Gilbert <gaetan.gilbert@skyskimmer.net> | 2017-11-09 17:27:58 +0100 |
|---|---|---|
| committer | Gaëtan Gilbert <gaetan.gilbert@skyskimmer.net> | 2018-02-10 01:34:19 +0100 |
| commit | 35fba70509d9fb219b2a88f8e7bd246b2671b39b (patch) | |
| tree | 21cdb9aa905ef8f6375aa6cd119254794233d0ac /pretyping/evarconv.ml | |
| parent | 10d3d803e6b57024dd15df7d61670ce42260948a (diff) | |
Simplification: cumulativity information is variance information.
Since cumulativity of an inductive type is the universe constraints
which make a term convertible with its universe-renamed copy, the only
constraints we can get are between a universe and its copy.
As such we do not need to be able to represent arbitrary constraints
between universes and copied universes in a double-sized ucontext,
instead we can just keep around an array describing whether a bound
universe is covariant, invariant or irrelevant (CIC has no
contravariant conversion rule).
Printing is fairly obtuse and should be improved: when we print the
CumulativityInfo we add marks to the universes of the instance: = for
invariant, + for covariant and * for irrelevant. ie
Record Foo@{i j k} := { foo : Type@{i} -> Type@{j} }.
Print Foo.
gives
Cumulative Record Foo : Type@{max(i+1, j+1)} := Build_Foo
{ foo : Type@{i} -> Type@{j} }
(* =i +j *k |= *)
Diffstat (limited to 'pretyping/evarconv.ml')
| -rw-r--r-- | pretyping/evarconv.ml | 14 |
1 files changed, 1 insertions, 13 deletions
diff --git a/pretyping/evarconv.ml b/pretyping/evarconv.ml index 41c4616f7..dc3acbc3e 100644 --- a/pretyping/evarconv.ml +++ b/pretyping/evarconv.ml @@ -353,19 +353,7 @@ let exact_ise_stack2 env evd f sk1 sk2 = let check_leq_inductives evd cumi u u' = let u = EConstr.EInstance.kind evd u in let u' = EConstr.EInstance.kind evd u' in - let length_ind_instance = - Univ.AUContext.size (Univ.ACumulativityInfo.univ_context cumi) - in - let ind_sbcst = Univ.ACumulativityInfo.subtyp_context cumi in - if not ((length_ind_instance = Univ.Instance.length u) && - (length_ind_instance = Univ.Instance.length u')) then - anomaly (Pp.str "Invalid inductive subtyping encountered!") - else - begin - let comp_subst = (Univ.Instance.append u u') in - let comp_cst = Univ.AUContext.instantiate comp_subst ind_sbcst in - Evd.add_constraints evd comp_cst - end + Evd.add_constraints evd (Reduction.get_cumulativity_constraints CUMUL cumi u u') let rec evar_conv_x ts env evd pbty term1 term2 = let term1 = whd_head_evar evd term1 in |