;----------------------------------------------
; Decimal Add1 (long version)
; INPUT FORMAT:  a number in base 10
; EXAMPLE INPUT: 79

; start at the leftmost digit

s1 0 0 R s1  ; find rightmost digit
s1 1 1 R s1
s1 2 2 R s1
s1 3 3 R s1
s1 4 4 R s1
s1 5 5 R s1
s1 6 6 R s1
s1 7 7 R s1
s1 8 8 R s1
s1 9 9 R s1
s1 _ _ L s2

s2 0 1 * s3  ; now at the rightmost digit
s2 1 2 * s3  ; so add 1
s2 2 3 * s3
s2 3 4 * s3
s2 4 5 * s3
s2 5 6 * s3
s2 6 7 * s3
s2 7 8 * s3
s2 8 9 * s3
s2 9 0 L s2   ; add 1 and carry to left
s2 _ 1 * halt ; in case we run off the front end

s3 0 0 L s3   ; move back to the leftmost digit
s3 1 1 L s3
s3 2 2 L s3
s3 3 3 L s3
s3 4 4 L s3
s3 5 5 L s3
s3 6 6 L s3
s3 7 7 L s3
s3 8 8 L s3
s3 9 9 L s3
s3 _ _ R halt ; halt at the leftmost digit

;----------------------------------------------
; Decimal Add1 (short version)
; INPUT FORMAT:  a number in base 10
; EXAMPLE INPUT: 79

; start at the leftmost digit

s1 * * R s1   ; * matches any symbol
s1 _ _ L s2
s2 0 1 * s3
s2 1 2 * s3
s2 2 3 * s3
s2 3 4 * s3
s2 4 5 * s3
s2 5 6 * s3
s2 6 7 * s3
s2 7 8 * s3
s2 8 9 * s3
s2 9 0 L s2
s2 _ 1 * halt
s3 * * L s3   ; * matches any symbol
s3 _ _ R halt

;----------------------------------------------