diff --git a/core/io/files/files.factor b/core/io/files/files.factor
index 7bd9599e4d..6e4648b590 100755
--- a/core/io/files/files.factor
+++ b/core/io/files/files.factor
@@ -35,7 +35,11 @@ M: object root-directory? ( path -- ? ) path-separator? ;
 : stat ( path -- directory? permissions length modified )
     normalize-pathname (stat) ;
 
-: exists? ( path -- ? ) stat >r 3drop r> >boolean ;
+: file-length ( path -- n ) stat 4array third ;
+
+: file-modified ( path -- n ) stat >r 3drop r> ; inline
+
+: exists? ( path -- ? ) file-modified >boolean ;
 
 : directory? ( path -- ? ) stat 3drop ;
 
@@ -52,10 +56,6 @@ M: object root-directory? ( path -- ? ) path-separator? ;
 : directory ( path -- seq )
     normalize-directory dup (directory) fixup-directory ;
 
-: file-length ( path -- n ) stat 4array third ;
-
-: file-modified ( path -- n ) stat >r 3drop r> ;
-
 : last-path-separator ( path -- n ? )
     [ length 2 [-] ] keep [ path-separator? ] find-last* ;
 
diff --git a/core/math/intervals/intervals.factor b/core/math/intervals/intervals.factor
index 0b4378aa8a..b7eb5be8c9 100644
--- a/core/math/intervals/intervals.factor
+++ b/core/math/intervals/intervals.factor
@@ -68,7 +68,7 @@ C: <interval> interval
 : (interval-op) ( p1 p2 quot -- p3 )
     2over >r >r
     >r [ first ] 2apply r> call
-    r> r> [ second ] 2apply and 2array ; inline
+    r> r> [ second ] both? 2array ; inline
 
 : interval-op ( i1 i2 quot -- i3 )
     pick interval-from pick interval-from pick (interval-op) >r
diff --git a/extra/combinators/cleave/cleave.factor b/extra/combinators/cleave/cleave.factor
index 85381ec499..e1e3585813 100644
--- a/extra/combinators/cleave/cleave.factor
+++ b/extra/combinators/cleave/cleave.factor
@@ -7,7 +7,7 @@ IN: combinators.cleave
 ! The cleaver family
 ! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
 
-: bi ( obj quot quot -- val val ) >r over slip r> call ; inline
+: bi ( obj quot quot -- val val ) >r keep r> call ; inline
 
 : tri ( obj quot quot quot -- val val val )
   >r pick >r bi r> r> call ; inline
@@ -23,7 +23,7 @@ IN: combinators.cleave
 ! The spread family
 ! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
 
-: bi* ( obj obj quot quot -- val val ) >r swap >r call r> r> call ; inline
+: bi* ( obj obj quot quot -- val val ) >r swap slip r> call ; inline
 
 : tri* ( obj obj obj quot quot quot -- val val val )
   >r rot >r bi* r> r> call ; inline
diff --git a/extra/random/random.factor b/extra/random/random.factor
index 6045da72d8..db2aacd2b0 100755
--- a/extra/random/random.factor
+++ b/extra/random/random.factor
@@ -36,7 +36,7 @@ SYMBOL: mt
 
 : set-mt-ith ( y i-get i-set -- )
     >r mt-nth >r
-    [ -1 shift ] keep odd? mt-a 0 ? r> bitxor bitxor r>
+    [ 2/ ] keep odd? mt-a 0 ? r> bitxor bitxor r>
     mt-seq set-nth ; inline
 
 : mt-y ( y1 y2 -- y )