diff --git a/basis/regexp/classes/classes-tests.factor b/basis/regexp/classes/classes-tests.factor
index 2253cd999a..9a210fb576 100644
--- a/basis/regexp/classes/classes-tests.factor
+++ b/basis/regexp/classes/classes-tests.factor
@@ -27,20 +27,23 @@ IN: regexp.classes.tests
 [ T{ primitive-class { class letter-class } } ] [ letter-class <primitive-class> dup 2array <and-class> ] unit-test
 [ T{ primitive-class { class letter-class } } ] [ letter-class <primitive-class> dup 2array <or-class> ] unit-test
 [ T{ or-class { seq { 2 3 1 } } } ] [ { 1 2 } <or-class> { 2 3 } <or-class> 2array <or-class> ] unit-test
+[ T{ or-class { seq { 3 2 } } } ] [ { 2 3 } <or-class> 1 <not-class> 2array <and-class> ] unit-test
+[ f ] [ t <not-class> ] unit-test
+[ t ] [ f <not-class> ] unit-test
 
 ! Making classes into nested conditionals
 
 [ V{ 1 2 3 4 } ] [ T{ and-class f { 1 T{ not-class f 2 } T{ or-class f { 3 4 } } 2 } } class>questions ] unit-test
-[ { 3 } ] [ { { t 3 } } table>condition ] unit-test
-[ { T{ primitive-class } } ] [ { { t 1 } { T{ primitive-class } 2 } } table>questions ] unit-test
-[ { { t 1 } { t 2 } } ] [ { { t 1 } { T{ primitive-class } 2 } } T{ primitive-class } t answer ] unit-test
-[ { { t 1 } } ] [ { { t 1 } { T{ primitive-class } 2 } } T{ primitive-class } f answer ] unit-test
-[ T{ condition f T{ primitive-class } { 1 2 } { 1 } } ] [ { { t 1 } { T{ primitive-class } 2 } } table>condition ] unit-test
+[ { 3 } ] [ { { 3 t } } table>condition ] unit-test
+[ { T{ primitive-class } } ] [ { { 1 t } { 2 T{ primitive-class } } } table>questions ] unit-test
+[ { { 1 t } { 2 t } } ] [ { { 1 t } { 2 T{ primitive-class } } } T{ primitive-class } t answer ] unit-test
+[ { { 1 t } } ] [ { { 1 t } { 2 T{ primitive-class } } } T{ primitive-class } f answer ] unit-test
+[ T{ condition f T{ primitive-class } { 1 2 } { 1 } } ] [ { { 1 t } { 2 T{ primitive-class } } } table>condition ] unit-test
 
 SYMBOL: foo
 SYMBOL: bar
 
-[ T{ condition f T{ primitive-class f bar } T{ condition f T{ primitive-class f foo } { 1 2 3 } { 1 3 } } T{ condition f T{ primitive-class f foo } { 1 2 } { 1 } } } ] [ { { t 1 } { T{ primitive-class f foo } 2 } { T{ primitive-class f bar } 3 } } table>condition ] unit-test
+[ T{ condition f T{ primitive-class f bar } T{ condition f T{ primitive-class f foo } { 1 2 3 } { 1 3 } } T{ condition f T{ primitive-class f foo } { 1 2 } { 1 } } } ] [ { { 1 t } { 2 T{ primitive-class f foo } } { 3 T{ primitive-class f bar } } } table>condition ] unit-test
 
 [ t ] [ foo <primitive-class> dup t replace-question ] unit-test
 [ f ] [ foo <primitive-class> dup f replace-question ] unit-test
diff --git a/basis/regexp/classes/classes.factor b/basis/regexp/classes/classes.factor
index 229197e507..f8fce02213 100644
--- a/basis/regexp/classes/classes.factor
+++ b/basis/regexp/classes/classes.factor
@@ -2,7 +2,7 @@
 ! See http://factorcode.org/license.txt for BSD license.
 USING: accessors kernel math math.order words combinators locals
 ascii unicode.categories combinators.short-circuit sequences
-fry macros arrays assocs sets ;
+fry macros arrays assocs sets classes ;
 IN: regexp.classes
 
 SINGLETONS: any-char any-char-no-nl
@@ -130,7 +130,13 @@ M: f combine-and
     nip t ;
 
 M: not-class combine-and
-    class>> = [ f t ] [ f f ] if ;
+    class>> 2dup = [ 2drop f t ] [
+        dup integer? [
+            2dup swap class-member?
+            [ 2drop f f ]
+            [ drop t ] if
+        ] [ 2drop f f ] if
+    ] if ;
 
 M: integer combine-and
     swap 2dup class-member? [ drop t ] [ 2drop f t ] if ;
@@ -151,9 +157,6 @@ M: not-class combine-or
 M: integer combine-or
     2dup swap class-member? [ drop t ] [ 2drop f f ] if ;
 
-MACRO: instance? ( class -- ? )
-    "predicate" word-prop ;
-
 : flatten ( seq class -- newseq )
     '[ dup _ instance? [ seq>> ] [ 1array ] if ] map concat ; inline
 
@@ -201,6 +204,9 @@ M: and-class <not-class>
 M: or-class <not-class>
     seq>> [ <not-class> ] map <and-class> ;
 
+M: t <not-class> drop f ;
+M: f <not-class> drop t ;
+
 M: not-class class-member?
     class>> class-member? not ;
 
@@ -230,8 +236,8 @@ M: not-class replace-question
     class>> replace-question <not-class> ;
 
 : answer ( table question answer -- new-table )
-    '[ [ _ _ replace-question ] dip ] assoc-map
-    [ drop ] assoc-filter ;
+    '[ _ _ replace-question ] assoc-map
+    [ nip ] assoc-filter ;
 
 DEFER: make-condition
 
@@ -242,7 +248,7 @@ DEFER: make-condition
     2dup = [ 2nip ] [ <condition> ] if ;
 
 : make-condition ( table questions -- condition )
-    [ values ] [ unclip (make-condition) ] if-empty ;
+    [ keys ] [ unclip (make-condition) ] if-empty ;
 
 GENERIC: class>questions ( class -- questions )
 : compound-questions ( class -- questions ) seq>> [ class>questions ] gather ;
@@ -252,9 +258,10 @@ M: not-class class>questions class>> class>questions ;
 M: object class>questions 1array ;
 
 : table>questions ( table -- questions )
-    keys <and-class> class>questions t swap remove ;
+    values <and-class> class>questions t swap remove ;
 
 : table>condition ( table -- condition )
+    ! input table is state => class
     >alist dup table>questions make-condition ;
 
 : condition-map ( condition quot: ( obj -- obj' ) -- new-condition ) 
diff --git a/basis/regexp/compiler/compiler.factor b/basis/regexp/compiler/compiler.factor
index 88fc415b42..30c9a5a5cb 100644
--- a/basis/regexp/compiler/compiler.factor
+++ b/basis/regexp/compiler/compiler.factor
@@ -18,9 +18,13 @@ IN: regexp.compiler
         [ [ 3drop ] ] [ '[ drop _ execute ] ] if-empty
     ] if ;
 
-: non-literals>dispatch ( non-literal-transitions -- quot )
+: new-non-literals>dispatch ( non-literal-transitions -- quot )
     table>condition condition>quot ;
 
+: non-literals>dispatch ( non-literal-transitions -- quot )
+    [ [ '[ dup _ class-member? ] ] [ '[ drop _ execute ] ] bi* ] assoc-map
+    [ 3drop ] suffix '[ _ cond ] ;
+
 : expand-one-or ( or-class transition -- alist )
     [ seq>> ] dip '[ _ 2array ] map ;
 
diff --git a/basis/regexp/dfa/dfa.factor b/basis/regexp/dfa/dfa.factor
index f05f5d5c7f..6ddc0396a7 100644
--- a/basis/regexp/dfa/dfa.factor
+++ b/basis/regexp/dfa/dfa.factor
@@ -29,7 +29,7 @@ IN: regexp.dfa
     '[ _ _ t epsilon-loop ] each ;
 
 : find-epsilon-closure ( states nfa -- dfa-state )
-    epsilon-table [ swap ] assoc-map table>condition ;
+    epsilon-table table>condition ;
 
 : find-closure ( states transition nfa -- new-states )
     [ find-delta ] keep find-epsilon-closure ;
@@ -59,18 +59,13 @@ IN: regexp.dfa
         nfa dfa new-states visited-states new-transitions
     ] if-empty ;
 
-: states ( hashtable -- array )
-    [ keys ]
-    [ values [ values concat ] map concat ] bi
-    append ;
-
 : set-final-states ( nfa dfa -- )
     [
         [ final-states>> keys ]
-        [ transitions>> states ] bi*
+        [ transitions>> keys ] bi*
         [ intersects? ] with filter
-    ] [ final-states>> ] bi
-    [ conjoin ] curry each ;
+        unique
+    ] keep (>>final-states) ;
 
 : initialize-dfa ( nfa -- dfa )
     <transition-table>
diff --git a/basis/regexp/minimize/minimize-tests.factor b/basis/regexp/minimize/minimize-tests.factor
index c5564caa55..8cbfaf4a71 100644
--- a/basis/regexp/minimize/minimize-tests.factor
+++ b/basis/regexp/minimize/minimize-tests.factor
@@ -1,7 +1,7 @@
 ! Copyright (C) 2009 Daniel Ehrenberg
 ! See http://factorcode.org/license.txt for BSD license.
 USING: tools.test regexp.minimize assocs regexp
-accessors regexp.transition-tables ;
+accessors regexp.transition-tables regexp.parser regexp.negation ;
 IN: regexp.minimize.tests
 
 [ t ] [ 1 2 H{ { { 1 2 } t } } same-partition? ] unit-test
@@ -13,13 +13,16 @@ IN: regexp.minimize.tests
 
 [ { { 1 2 } { 3 4 } } ] [ H{ { "elephant" 1 } { "tiger" 3 } } H{ { "elephant" 2 } { "tiger" 4 } } assemble-values ] unit-test
 
-[ 3 ] [ R/ ab|ac/ dfa>> transitions>> assoc-size ] unit-test
-[ 3 ] [ R/ a(b|c)/ dfa>> transitions>> assoc-size ] unit-test
-[ 1 ] [ R/ ((aa*)*)*/ dfa>> transitions>> assoc-size ] unit-test
-[ 1 ] [ R/ a|((aa*)*)*/ dfa>> transitions>> assoc-size ] unit-test
-[ 2 ] [ R/ ab|((aa*)*)*b/ dfa>> transitions>> assoc-size ] unit-test
-[ 4 ] [ R/ ab|cd/ dfa>> transitions>> assoc-size ] unit-test
-[ 1 ] [ R/ [a-z]*|[A-Z]*/i dfa>> transitions>> assoc-size ] unit-test
+: regexp-states ( string -- n )
+    parse-regexp ast>dfa transitions>> assoc-size ;
+
+[ 3 ] [ "ab|ac" regexp-states ] unit-test
+[ 3 ] [ "a(b|c)" regexp-states ] unit-test
+[ 1 ] [ "((aa*)*)*" regexp-states ] unit-test
+[ 1 ] [ "a|((aa*)*)*" regexp-states ] unit-test
+[ 2 ] [ "ab|((aa*)*)*b" regexp-states ] unit-test
+[ 4 ] [ "ab|cd" regexp-states ] unit-test
+[ 1 ] [ "(?i:[a-z]*|[A-Z]*)" regexp-states ] unit-test
 
 [
     T{ transition-table
diff --git a/basis/regexp/regexp.factor b/basis/regexp/regexp.factor
index ab091a7682..1bd242315f 100644
--- a/basis/regexp/regexp.factor
+++ b/basis/regexp/regexp.factor
@@ -48,7 +48,7 @@ C: <reverse-matcher> reverse-matcher
     ] change-reverse-dfa ;
 
 M: regexp match-index-from ( string regexp -- index/f )
-    compile-regexp dfa-quot>> <quot-matcher> match-index-from ;
+    compile-regexp dfa>> <quot-matcher> match-index-from ;
 
 M: reverse-matcher match-index-from ( string regexp -- index/f )
     [ <reversed> ] [ regexp>> compile-reverse reverse-dfa>> ] bi*
@@ -81,7 +81,7 @@ M: reverse-matcher match-index-from ( string regexp -- index/f )
 
 : parsing-regexp ( accum end -- accum )
     lexer get [ take-until ] [ parse-noblank-token ] bi
-    <optioned-regexp> compile-dfa-quot parsed ;
+    <optioned-regexp> compile-regexp parsed ;
 
 PRIVATE>