Move short to core

core/sequences/sequences.factor

@@ -206,6 +206,8 @@ M: slice virtual@ [ slice-from + ] [ slice-seq ] bi ;
 
 M: slice length dup slice-to swap slice-from - ;
 
+: short ( seq n -- seq n' ) over length min ; inline
+
 : head-slice ( seq n -- slice ) (head) <slice> ;
 
 : tail-slice ( seq n -- slice ) (tail) <slice> ;

extra/sequences/lib/lib.factor

@@ -234,9 +234,6 @@ PRIVATE>
 : remove-nth ( seq n -- seq' )
     cut-slice rest-slice append ;
 
-: short ( seq n -- seq n' )
-    over length min ; inline
-
 : if-seq ( seq quot1 quot2 -- )
     [ f like ] 2dip if* ; inline