Description: A positive integer which is not 1 is greater than or equal to 2. (Contributed by Glauco Siliprandi, 11-Dec-2019)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | nnne1ge2 | |- ( ( N e. NN /\ N =/= 1 ) -> 2 <_ N ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | nnnn0 | |- ( N e. NN -> N e. NN0 ) | |
| 2 | 1 | adantr | |- ( ( N e. NN /\ N =/= 1 ) -> N e. NN0 ) | 
| 3 | nnne0 | |- ( N e. NN -> N =/= 0 ) | |
| 4 | 3 | adantr | |- ( ( N e. NN /\ N =/= 1 ) -> N =/= 0 ) | 
| 5 | simpr | |- ( ( N e. NN /\ N =/= 1 ) -> N =/= 1 ) | |
| 6 | nn0n0n1ge2 | |- ( ( N e. NN0 /\ N =/= 0 /\ N =/= 1 ) -> 2 <_ N ) | |
| 7 | 2 4 5 6 | syl3anc | |- ( ( N e. NN /\ N =/= 1 ) -> 2 <_ N ) |