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[helm.git] / helm / software / components / tactics / proofEngineReduction.ml

diff --git a/helm/software/components/tactics/proofEngineReduction.ml b/helm/software/components/tactics/proofEngineReduction.ml
index c359313dd1e87e1ec88d1ef8684c46d6e48e3098..dbc98f722313e250ed0327c427c2aaaaffa9b280 100644 (file)
--- a/helm/software/components/tactics/proofEngineReduction.ml
+++ b/helm/software/components/tactics/proofEngineReduction.ml
@@ -122,7 +122,11 @@ let alpha_equivalence =
 
 exception WhatAndWithWhatDoNotHaveTheSameLength;;
 
-(* "textual" replacement of several subterms with other ones *)
+(* Replaces "textually" in "where" every term in "what" with the corresponding
+   term in "with_what". The terms in "what" ARE NOT lifted when binders are
+   crossed. The terms in "with_what" ARE NOT lifted when binders are crossed.
+   Every free variable in "where" IS NOT lifted by nnn.
+*)
 let replace ~equality ~what ~with_what ~where =
   let find_image t =
    let rec find_image_aux =
@@ -182,8 +186,13 @@ let replace ~equality ~what ~with_what ~where =
     aux where
 ;;
 
-(* replaces in a term a term with another one. *)
-(* Lifting are performed as usual.             *)
+(* Replaces in "where" every term in "what" with the corresponding
+   term in "with_what". The terms in "what" ARE lifted when binders are
+   crossed. The terms in "with_what" ARE lifted when binders are crossed.
+   Every free variable in "where" IS NOT lifted by nnn.
+   Thus "replace_lifting_csc 1 ~with_what:[Rel 1; ... ; Rel 1]" is the
+   inverse of subst up to the fact that free variables in "where" are NOT
+   lifted.  *)
 let replace_lifting ~equality ~what ~with_what ~where =
   let find_image what t =
    let rec find_image_aux =
@@ -278,8 +287,12 @@ let replace_lifting ~equality ~what ~with_what ~where =
   substaux 1 what where
 ;;
 
-(* replaces in a term a list of terms with other ones. *)
-(* Lifting are performed as usual.                     *)
+(* Replaces in "where" every term in "what" with the corresponding
+   term in "with_what". The terms in "what" ARE NOT lifted when binders are
+   crossed. The terms in "with_what" ARE lifted when binders are crossed.
+   Every free variable in "where" IS lifted by nnn.
+   Thus "replace_lifting_csc 1 ~with_what:[Rel 1; ... ; Rel 1]" is the
+   inverse of subst up to the fact that "what" terms are NOT lifted. *)
 let replace_lifting_csc nnn ~equality ~what ~with_what ~where =
   let find_image t =
    let rec find_image_aux =