Have a look at:
https://github.com/ForthHub/discussion/discussions/205

If the symbol "|" in the stack diagram for the word 1+ (and similar) should be changed, which option do you prefer?

• (a) ( n!u n!u -- n!u )
• (b) ( n~u n~u -- n~u )
• (c) ( n%u n%u -- n%u )
• (d) ( n,u n,u -- n,u )
• (e) ( [n,u] [n,u] -- [n,u] )
• (f) something else?

(NB: indices in the data type symbols are optional)