     { +secondary+ t }
 } define-operation
 
+! Thread
+: com-thread-traceback-window ( thread -- )
+    continuation>> dup occupied>>
+    [ value>> traceback-window ]
+    [ drop beep ]
+    if ;
+
+[ thread? ] \ com-thread-traceback-window H{
+    { +primary+ t }
+    { +secondary+ t }
+} define-operation
+
 ! Pathnames
 : edit-file ( pathname -- ) edit ;
 

[ word? ] \ com-stack-effect H{
    { +listener+ t }
} define-operation

! Vocabularies
! : com-vocab-words ( vocab -- )
!     get-workspace swap show-vocab-words ;

! [ vocab? ] \ com-vocab-words H{
!     { +secondary+ t }
!     { +keyboard+ T{ key-down f { C+ } "B" } }
! } define-operation

: com-enter-in ( vocab -- ) vocab-name set-in ;



[ definition? ] \ com-forget H{ } define-operation

[ topic? ] \ com-follow H{
    { +keyboard+ T{ key-down f { C+ } "h" } }
    { +primary+ t }
} define-operation

[ word? ] \ usage. H{
    { +keyboard+ T{ key-down f { C+ } "u" } }
} define-operation

[ word? ] \ fix H{
    { +keyboard+ T{ key-down f { C+ } "f" } }
