diff --git a/core/assocs/assocs-docs.factor b/core/assocs/assocs-docs.factor
index 2eabe9b0bc..ed82532d0c 100755
--- a/core/assocs/assocs-docs.factor
+++ b/core/assocs/assocs-docs.factor
@@ -59,6 +59,7 @@ ARTICLE: "assocs-sets" "Set-theoretic operations on assocs"
 { $subsection diff }
 { $subsection remove-all }
 { $subsection substitute }
+{ $subsection substitute-here }
 { $see-also key? } ;
 
 ARTICLE: "assocs-mutation" "Storing keys and values in assocs"
@@ -266,12 +267,16 @@ HELP: remove-all
 { $notes "The values of the keys in the assoc are disregarded, so this word is usually used for set-theoretic calculations where the assoc in question either has dummy sentinels as values, or the values equal the keys." }
 { $side-effects "assoc" } ;
 
-HELP: substitute
+HELP: substitute-here
 { $values { "assoc" assoc } { "seq" "a mutable sequence" } }
-{ $description "Replaces elements of " { $snippet "seq" } " which appear in as keys in " { $snippet "assoc" } " with the corresponding values, acting as the identity on all other elements." }
+{ $description "Replaces elements of " { $snippet "seq" } " which appear as keys in " { $snippet "assoc" } " with the corresponding values, acting as the identity on all other elements." }
 { $errors "Throws an error if " { $snippet "assoc" } " contains values whose types are not permissible in " { $snippet "seq" } "." }
 { $side-effects "seq" } ;
 
+HELP: substitute
+{ $values { "assoc" assoc } { "seq" sequence } { "seq" sequence } }
+{ $description "Creates a new sequence where elements of " { $snippet "seq" } " which appear as keys in " { $snippet "assoc" } " are replaced by the corresponding values, and all other elements are unchanged." } ;
+
 HELP: cache
 { $values { "key" "a key" } { "assoc" assoc } { "quot" "a quotation with stack effect " { $snippet "( key -- value )" } } { "value" "a previously-retained or freshly-computed value" } }
 { $description "If the key is present in the assoc, outputs the associated value, otherwise calls the quotation to produce a value and stores the key/value pair into the assoc." }
diff --git a/core/assocs/assocs.factor b/core/assocs/assocs.factor
index d8cf01e1bd..ff0938e001 100755
--- a/core/assocs/assocs.factor
+++ b/core/assocs/assocs.factor
@@ -124,8 +124,14 @@ M: assoc assoc-clone-like ( assoc exemplar -- newassoc )
 : remove-all ( assoc seq -- subseq )
     swap [ key? not ] curry subset ;
 
-: substitute ( assoc seq -- )
-    swap [ dupd at* [ nip ] [ drop ] if ] curry change-each ;
+: (substitute)
+    [ dupd at* [ nip ] [ drop ] if ] curry ; inline
+
+: substitute-here ( seq assoc -- )
+    (substitute) change-each ;
+
+: substitute ( seq assoc -- newseq )
+    (substitute) map ;
 
 : cache ( key assoc quot -- value )
     2over at [
diff --git a/core/generator/registers/registers.factor b/core/generator/registers/registers.factor
old mode 100644
new mode 100755
index 8dc9bd606f..307e3a99f1
--- a/core/generator/registers/registers.factor
+++ b/core/generator/registers/registers.factor
@@ -504,7 +504,7 @@ M: loc lazy-store
 : substitute-vregs ( values vregs -- )
     [ vreg-substitution ] 2map
     [ substitute-vreg? ] assoc-subset >hashtable
-    [ swap substitute ] curry each-phantom ;
+    [ substitute-here ] curry each-phantom ;
 
 : set-operand ( value var -- )
     >r dup constant? [ constant-value ] when r> set ;
diff --git a/core/optimizer/backend/backend.factor b/core/optimizer/backend/backend.factor
index 3fe3a3e25f..d13df9e70c 100755
--- a/core/optimizer/backend/backend.factor
+++ b/core/optimizer/backend/backend.factor
@@ -37,10 +37,10 @@ GENERIC: optimize-node* ( node -- node/t changed? )
     over assoc-empty? [
         2drop
     ] [
-        2dup node-in-d substitute
-        2dup node-in-r substitute
-        2dup node-out-d substitute
-        node-out-r substitute
+        2dup node-in-d substitute-here
+        2dup node-in-r substitute-here
+        2dup node-out-d substitute-here
+        node-out-r substitute-here
     ] if ;
 
 : perform-substitutions ( node -- )
diff --git a/core/vocabs/loader/loader.factor b/core/vocabs/loader/loader.factor
index 5e8a5630b2..a05cd2fa8c 100755
--- a/core/vocabs/loader/loader.factor
+++ b/core/vocabs/loader/loader.factor
@@ -1,10 +1,10 @@
 ! Copyright (C) 2007, 2008 Eduardo Cavazos, Slava Pestov.
 ! See http://factorcode.org/license.txt for BSD license.
-USING: namespaces splitting sequences io.files kernel assocs
-words vocabs definitions parser continuations inspector debugger
-io io.styles io.streams.lines hashtables sorting prettyprint
-source-files arrays combinators strings system math.parser
-compiler.errors ;
+USING: namespaces sequences io.files kernel assocs words vocabs
+definitions parser continuations inspector debugger io io.styles
+io.streams.lines hashtables sorting prettyprint source-files
+arrays combinators strings system math.parser compiler.errors
+splitting ;
 IN: vocabs.loader
 
 SYMBOL: vocab-roots
@@ -16,7 +16,7 @@ V{
 } clone vocab-roots set-global
 
 : vocab-dir ( vocab -- dir )
-    vocab-name "." split "/" join ;
+    vocab-name { { CHAR: . CHAR: / } } substitute ;
 
 : vocab-dir+ ( vocab str/f -- path )
     >r vocab-name "." split r>
diff --git a/extra/sequences/lib/lib.factor b/extra/sequences/lib/lib.factor
index 4c0ea04f24..1beec90b75 100755
--- a/extra/sequences/lib/lib.factor
+++ b/extra/sequences/lib/lib.factor
@@ -205,6 +205,3 @@ PRIVATE>
 
 : attempt-each ( seq quot -- result )
     (each) iterate-prep (attempt-each-integer) ; inline
-
-: replace ( seq old new -- newseq )
-    [ pick pick = [ 2nip ] [ 2drop ] if ] 2curry map ;
diff --git a/extra/tools/disassembler/disassembler.factor b/extra/tools/disassembler/disassembler.factor
index 16ea58ac70..8fe3b9bdf0 100755
--- a/extra/tools/disassembler/disassembler.factor
+++ b/extra/tools/disassembler/disassembler.factor
@@ -2,7 +2,7 @@
 ! See http://factorcode.org/license.txt for BSD license.
 USING: io.files io words alien kernel math.parser alien.syntax
 io.launcher system assocs arrays sequences namespaces qualified
-system math sequences.lib windows.kernel32 generator.fixup ;
+system math windows.kernel32 generator.fixup ;
 IN: tools.disassembler
 
 : in-file "gdb-in.txt" resource-path ;
@@ -31,7 +31,7 @@ M: pair make-disassemble-cmd
     out-file file-lines ;
 
 : tabs>spaces ( str -- str' )
-    CHAR: \t CHAR: \s replace ;
+    { { CHAR: \t CHAR: \s } } substitute ;
 
 : disassemble ( word -- )
     make-disassemble-cmd run-gdb
diff --git a/extra/unicode/data/data.factor b/extra/unicode/data/data.factor
old mode 100644
new mode 100755
index 419d3bcefd..c3998a6132
--- a/extra/unicode/data/data.factor
+++ b/extra/unicode/data/data.factor
@@ -1,7 +1,6 @@
-USING: assocs math kernel sequences sequences.lib io.files
-hashtables quotations splitting arrays math.parser
-combinators.lib hash2 byte-arrays words namespaces words
-compiler.units parser ;
+USING: assocs math kernel sequences io.files hashtables
+quotations splitting arrays math.parser combinators.lib hash2
+byte-arrays words namespaces words compiler.units parser ;
 IN: unicode.data
 
 <<
@@ -68,7 +67,7 @@ IN: unicode.data
 : process-combining ( data -- hash )
     3 swap (process-data)
     [ string>number ] assoc-map
-    [ nip 0 = not ] assoc-subset
+    [ nip zero? not ] assoc-subset
     >hashtable ;
 
 : categories ( -- names )
@@ -95,9 +94,9 @@ IN: unicode.data
     [ dup CHAR: A CHAR: Z between? [ HEX: 20 + ] when ] map ;
 
 : process-names ( data -- names-hash )
-    1 swap (process-data)
-    [ ascii-lower CHAR: \s CHAR: - replace swap ] assoc-map
-    >hashtable ;
+    1 swap (process-data) [
+        ascii-lower { { CHAR: \s CHAR: - } } substitute swap
+    ] assoc-map >hashtable ;
 
 : multihex ( hexstring -- string )
     " " split [ hex> ] map [ ] subset ;