From 35fba70509d9fb219b2a88f8e7bd246b2671b39b Mon Sep 17 00:00:00 2001 From: Gaëtan Gilbert Date: Thu, 9 Nov 2017 17:27:58 +0100 Subject: 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 |= *) --- checker/values.ml | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'checker/values.ml') diff --git a/checker/values.ml b/checker/values.ml index 313067cb6..55e1cdb6f 100644 --- a/checker/values.ml +++ b/checker/values.ml @@ -110,10 +110,12 @@ let v_cstrs = (v_tuple "univ_constraint" [|v_level;v_enum "order_request" 3;v_level|])) +let v_variance = v_enum "variance" 3 + let v_instance = Annot ("instance", Array v_level) let v_context = v_tuple "universe_context" [|v_instance;v_cstrs|] let v_abs_context = v_context (* only for clarity *) -let v_abs_cum_info = v_tuple "cumulativity_info" [|v_abs_context; v_context|] +let v_abs_cum_info = v_tuple "cumulativity_info" [|v_abs_context; Array v_variance|] let v_context_set = v_tuple "universe_context_set" [|v_hset v_level;v_cstrs|] (** kernel/term *) -- cgit v1.2.3