6.1.0290
1+
one-plus
CORE
 
( n1 | u1 -- n2 | u2 )

Add one (1) to n1 | u1 giving the sum n2 | u2.

Testing:
T{        0 1+ ->          1 }T
T{       -1 1+ ->          0 }T
T{        1 1+ ->          2 }T
T{ MID-UINT 1+ -> MID-UINT+1 }T