Metamath Proof Explorer


Theorem ge2nprmge4

Description: A composite integer greater than or equal to 2 is greater than or equal to 4 . (Contributed by AV, 5-Jun-2023)

Ref Expression
Assertion ge2nprmge4 X2XX4

Proof

Step Hyp Ref Expression
1 eluz2b2 X2X1<X
2 4z 4
3 2 a1i X1<XX4
4 nnz XX
5 4 ad2antrr X1<XXX
6 1z 1
7 zltp1le 1X1<X1+1X
8 6 4 7 sylancr X1<X1+1X
9 1p1e2 1+1=2
10 9 breq1i 1+1X2X
11 8 10 bitrdi X1<X2X
12 2re 2
13 nnre XX
14 leloe 2X2X2<X2=X
15 12 13 14 sylancr X2X2<X2=X
16 2z 2
17 zltp1le 2X2<X2+1X
18 16 4 17 sylancr X2<X2+1X
19 2p1e3 2+1=3
20 19 breq1i 2+1X3X
21 18 20 bitrdi X2<X3X
22 3re 3
23 leloe 3X3X3<X3=X
24 22 13 23 sylancr X3X3<X3=X
25 df-4 4=3+1
26 3z 3
27 zltp1le 3X3<X3+1X
28 26 4 27 sylancr X3<X3+1X
29 28 biimpa X3<X3+1X
30 25 29 eqbrtrid X3<X4X
31 30 a1d X3<XX4X
32 31 ex X3<XX4X
33 neleq1 X=3X3
34 33 eqcoms 3=XX3
35 3prm 3
36 pm2.24nel 334X
37 35 36 mp1i 3=X34X
38 34 37 sylbid 3=XX4X
39 38 a1i X3=XX4X
40 32 39 jaod X3<X3=XX4X
41 24 40 sylbid X3XX4X
42 21 41 sylbid X2<XX4X
43 neleq1 X=2X2
44 43 eqcoms 2=XX2
45 2prm 2
46 pm2.24nel 224X
47 45 46 mp1i 2=X24X
48 44 47 sylbid 2=XX4X
49 48 a1i X2=XX4X
50 42 49 jaod X2<X2=XX4X
51 15 50 sylbid X2XX4X
52 11 51 sylbid X1<XX4X
53 52 imp X1<XX4X
54 53 imp X1<XX4X
55 3 5 54 3jca X1<XX4X4X
56 55 ex X1<XX4X4X
57 eluz2 X44X4X
58 56 57 syl6ibr X1<XXX4
59 1 58 sylbi X2XX4
60 59 imp X2XX4