Description: 5 is a prime number. (Contributed by Mario Carneiro, 18-Feb-2014) (Revised by Mario Carneiro, 20-Apr-2015)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | 5prm | |- 5 e. Prime | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | 5nn | |- 5 e. NN | |
| 2 | 1lt5 | |- 1 < 5 | |
| 3 | 2nn | |- 2 e. NN | |
| 4 | 2nn0 | |- 2 e. NN0 | |
| 5 | 1nn | |- 1 e. NN | |
| 6 | 2t2e4 | |- ( 2 x. 2 ) = 4 | |
| 7 | 6 | oveq1i | |- ( ( 2 x. 2 ) + 1 ) = ( 4 + 1 ) | 
| 8 | df-5 | |- 5 = ( 4 + 1 ) | |
| 9 | 7 8 | eqtr4i | |- ( ( 2 x. 2 ) + 1 ) = 5 | 
| 10 | 1lt2 | |- 1 < 2 | |
| 11 | 3 4 5 9 10 | ndvdsi | |- -. 2 || 5 | 
| 12 | 3nn | |- 3 e. NN | |
| 13 | 1nn0 | |- 1 e. NN0 | |
| 14 | 3t1e3 | |- ( 3 x. 1 ) = 3 | |
| 15 | 14 | oveq1i | |- ( ( 3 x. 1 ) + 2 ) = ( 3 + 2 ) | 
| 16 | 3p2e5 | |- ( 3 + 2 ) = 5 | |
| 17 | 15 16 | eqtri | |- ( ( 3 x. 1 ) + 2 ) = 5 | 
| 18 | 2lt3 | |- 2 < 3 | |
| 19 | 12 13 3 17 18 | ndvdsi | |- -. 3 || 5 | 
| 20 | 5nn0 | |- 5 e. NN0 | |
| 21 | 5lt10 | |- 5 < ; 1 0 | |
| 22 | 3 20 20 21 | declti | |- 5 < ; 2 5 | 
| 23 | 1 2 11 19 22 | prmlem1 | |- 5 e. Prime |