Description: The successor of a decimal integer (no carry). (Contributed by Mario Carneiro, 18-Feb-2014)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | numnncl.1 | |- T e. NN0 |
|
| numnncl.2 | |- A e. NN0 |
||
| numcl.2 | |- B e. NN0 |
||
| numsuc.4 | |- ( B + 1 ) = C |
||
| numsuc.5 | |- N = ( ( T x. A ) + B ) |
||
| Assertion | numsuc | |- ( N + 1 ) = ( ( T x. A ) + C ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | numnncl.1 | |- T e. NN0 |
|
| 2 | numnncl.2 | |- A e. NN0 |
|
| 3 | numcl.2 | |- B e. NN0 |
|
| 4 | numsuc.4 | |- ( B + 1 ) = C |
|
| 5 | numsuc.5 | |- N = ( ( T x. A ) + B ) |
|
| 6 | 5 | oveq1i | |- ( N + 1 ) = ( ( ( T x. A ) + B ) + 1 ) |
| 7 | 1 2 | nn0mulcli | |- ( T x. A ) e. NN0 |
| 8 | 7 | nn0cni | |- ( T x. A ) e. CC |
| 9 | 3 | nn0cni | |- B e. CC |
| 10 | ax-1cn | |- 1 e. CC |
|
| 11 | 8 9 10 | addassi | |- ( ( ( T x. A ) + B ) + 1 ) = ( ( T x. A ) + ( B + 1 ) ) |
| 12 | 4 | oveq2i | |- ( ( T x. A ) + ( B + 1 ) ) = ( ( T x. A ) + C ) |
| 13 | 6 11 12 | 3eqtri | |- ( N + 1 ) = ( ( T x. A ) + C ) |