| Step |
Hyp |
Ref |
Expression |
| 1 |
|
n0sno |
|- ( M e. NN0_s -> M e. No ) |
| 2 |
1
|
adantr |
|- ( ( M e. NN0_s /\ N e. NN0_s ) -> M e. No ) |
| 3 |
|
n0sno |
|- ( N e. NN0_s -> N e. No ) |
| 4 |
3
|
adantl |
|- ( ( M e. NN0_s /\ N e. NN0_s ) -> N e. No ) |
| 5 |
|
1sno |
|- 1s e. No |
| 6 |
5
|
a1i |
|- ( ( M e. NN0_s /\ N e. NN0_s ) -> 1s e. No ) |
| 7 |
2 4 6
|
sleadd1d |
|- ( ( M e. NN0_s /\ N e. NN0_s ) -> ( M <_s N <-> ( M +s 1s ) <_s ( N +s 1s ) ) ) |
| 8 |
|
peano2n0s |
|- ( N e. NN0_s -> ( N +s 1s ) e. NN0_s ) |
| 9 |
|
n0sltp1le |
|- ( ( M e. NN0_s /\ ( N +s 1s ) e. NN0_s ) -> ( M ( M +s 1s ) <_s ( N +s 1s ) ) ) |
| 10 |
8 9
|
sylan2 |
|- ( ( M e. NN0_s /\ N e. NN0_s ) -> ( M ( M +s 1s ) <_s ( N +s 1s ) ) ) |
| 11 |
7 10
|
bitr4d |
|- ( ( M e. NN0_s /\ N e. NN0_s ) -> ( M <_s N <-> M |