Metamath Proof Explorer


Theorem catstr

Description: A category structure is a structure. (Contributed by Mario Carneiro, 3-Jan-2017)

Ref Expression
Assertion catstr ⊢ Base ndx U Hom ⁡ ndx H comp ⁡ ndx · ˙ Struct 1 15

Proof

Step Hyp Ref Expression
1 1nn ⊢ 1 ∈ ℕ
2 basendx ⊢ Base ndx = 1
3 4nn0 ⊢ 4 ∈ ℕ 0
4 1nn0 ⊢ 1 ∈ ℕ 0
5 1lt10 ⊢ 1 < 10
6 1 3 4 5 declti ⊢ 1 < 14
7 4nn ⊢ 4 ∈ ℕ
8 4 7 decnncl ⊢ 14 ∈ ℕ
9 homndx ⊢ Hom ⁡ ndx = 14
10 5nn ⊢ 5 ∈ ℕ
11 4lt5 ⊢ 4 < 5
12 4 3 10 11 declt ⊢ 14 < 15
13 4 10 decnncl ⊢ 15 ∈ ℕ
14 ccondx ⊢ comp ⁡ ndx = 15
15 1 2 6 8 9 12 13 14 strle3 ⊢ Base ndx U Hom ⁡ ndx H comp ⁡ ndx · ˙ Struct 1 15