Metamath Proof Explorer


Theorem 23prm

Description: 23 is a prime number. (Contributed by Mario Carneiro, 18-Feb-2014) (Revised by Mario Carneiro, 20-Apr-2015)

Ref Expression
Assertion 23prm
|- ; 2 3 e. Prime

Proof

Step Hyp Ref Expression
1 2nn0
 |-  2 e. NN0
2 3nn
 |-  3 e. NN
3 1 2 decnncl
 |-  ; 2 3 e. NN
4 2nn
 |-  2 e. NN
5 3nn0
 |-  3 e. NN0
6 1nn0
 |-  1 e. NN0
7 1lt10
 |-  1 < ; 1 0
8 4 5 6 7 declti
 |-  1 < ; 2 3
9 4 nncni
 |-  2 e. CC
10 9 mulid2i
 |-  ( 1 x. 2 ) = 2
11 df-3
 |-  3 = ( 2 + 1 )
12 1 6 10 11 dec2dvds
 |-  -. 2 || ; 2 3
13 7nn0
 |-  7 e. NN0
14 7cn
 |-  7 e. CC
15 2 nncni
 |-  3 e. CC
16 7t3e21
 |-  ( 7 x. 3 ) = ; 2 1
17 14 15 16 mulcomli
 |-  ( 3 x. 7 ) = ; 2 1
18 1p2e3
 |-  ( 1 + 2 ) = 3
19 1 6 1 17 18 decaddi
 |-  ( ( 3 x. 7 ) + 2 ) = ; 2 3
20 2lt3
 |-  2 < 3
21 2 13 4 19 20 ndvdsi
 |-  -. 3 || ; 2 3
22 5nn
 |-  5 e. NN
23 3lt5
 |-  3 < 5
24 1 5 22 23 declt
 |-  ; 2 3 < ; 2 5
25 3 8 12 21 24 prmlem1
 |-  ; 2 3 e. Prime