Metamath Proof Explorer


Theorem numsuc

Description: The successor of a decimal integer (no carry). (Contributed by Mario Carneiro, 18-Feb-2014)

Ref Expression
Hypotheses numnncl.1 T 0
numnncl.2 A 0
numcl.2 B 0
numsuc.4 B + 1 = C
numsuc.5 N = T A + B
Assertion numsuc N + 1 = T A + C

Proof

Step Hyp Ref Expression
1 numnncl.1 T 0
2 numnncl.2 A 0
3 numcl.2 B 0
4 numsuc.4 B + 1 = C
5 numsuc.5 N = T A + B
6 5 oveq1i N + 1 = T A + B + 1
7 1 2 nn0mulcli T A 0
8 7 nn0cni T A
9 3 nn0cni B
10 ax-1cn 1
11 8 9 10 addassi T A + B + 1 = T A + B + 1
12 4 oveq2i T A + B + 1 = T A + C
13 6 11 12 3eqtri N + 1 = T A + C