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author | Benjamin Barenblat <bbaren@debian.org> | 2019-02-02 19:29:23 -0500 |
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committer | Benjamin Barenblat <bbaren@debian.org> | 2019-02-02 19:29:23 -0500 |
commit | 9ebf44d84754adc5b64fcf612c6816c02c80462d (patch) | |
tree | bf5e06a28488e0e06a2f2011ff0d110e2e02f8fc /kernel/esubst.ml | |
parent | 9043add656177eeac1491a73d2f3ab92bec0013c (diff) |
Imported Upstream version 8.9.0upstream/8.9.0upstream
Diffstat (limited to 'kernel/esubst.ml')
-rw-r--r-- | kernel/esubst.ml | 35 |
1 files changed, 30 insertions, 5 deletions
diff --git a/kernel/esubst.ml b/kernel/esubst.ml index a11a0dc0..9fc3b11d 100644 --- a/kernel/esubst.ml +++ b/kernel/esubst.ml @@ -19,6 +19,8 @@ open Util (*********************) (* Explicit lifts and basic operations *) +(* Invariant to preserve in this module: no lift contains two consecutive + [ELSHFT] nor two consecutive [ELLFT]. *) type lift = | ELID | ELSHFT of lift * int (* ELSHFT(l,n) == lift of n, then apply lift l *) @@ -28,15 +30,15 @@ type lift = let el_id = ELID (* compose a relocation of magnitude n *) -let rec el_shft_rec n = function - | ELSHFT(el,k) -> el_shft_rec (k+n) el +let el_shft_rec n = function + | ELSHFT(el,k) -> ELSHFT(el,k+n) | el -> ELSHFT(el,n) let el_shft n el = if Int.equal n 0 then el else el_shft_rec n el (* cross n binders *) -let rec el_liftn_rec n = function +let el_liftn_rec n = function | ELID -> ELID - | ELLFT(k,el) -> el_liftn_rec (n+k) el + | ELLFT(k,el) -> ELLFT(n+k, el) | el -> ELLFT(n, el) let el_liftn n el = if Int.equal n 0 then el else el_liftn_rec n el @@ -132,13 +134,36 @@ let rec exp_rel lams k subs = let expand_rel k subs = exp_rel 0 k subs +let rec subs_map f = function +| ESID _ as s -> s +| CONS (x, s) -> CONS (Array.map f x, subs_map f s) +| SHIFT (n, s) -> SHIFT (n, subs_map f s) +| LIFT (n, s) -> LIFT (n, subs_map f s) + +let rec lift_subst mk_cl s1 s2 = match s1 with +| ELID -> subs_map (fun c -> mk_cl ELID c) s2 +| ELSHFT(s, k) -> subs_shft(k, lift_subst mk_cl s s2) +| ELLFT (k, s) -> + match s2 with + | CONS(x,s') -> + CONS(CArray.Fun1.map mk_cl s1 x, lift_subst mk_cl s1 s') + | ESID n -> lift_subst mk_cl s (ESID (n + k)) + | SHIFT(k',s') -> + if k<k' + then subs_shft(k, lift_subst mk_cl s (subs_shft(k'-k, s'))) + else subs_shft(k', lift_subst mk_cl (el_liftn (k-k') s) s') + | LIFT(k',s') -> + if k<k' + then subs_liftn k (lift_subst mk_cl s (subs_liftn (k'-k) s')) + else subs_liftn k' (lift_subst mk_cl (el_liftn (k-k') s) s') + let rec comp mk_cl s1 s2 = match (s1, s2) with | _, ESID _ -> s1 | ESID _, _ -> s2 | SHIFT(k,s), _ -> subs_shft(k, comp mk_cl s s2) | _, CONS(x,s') -> - CONS(CArray.Fun1.map (fun s t -> mk_cl(s,t)) s1 x, comp mk_cl s1 s') + CONS(Array.Fun1.map (fun s t -> mk_cl(s,t)) s1 x, comp mk_cl s1 s') | CONS(x,s), SHIFT(k,s') -> let lg = Array.length x in if k == lg then comp mk_cl s s' |