Metamath Proof Explorer


Theorem catstr

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

Ref Expression
Assertion catstr BasendxUHomndxHcompndx·˙Struct115

Proof

Step Hyp Ref Expression
1 1nn 1
2 basendx Basendx=1
3 4nn0 40
4 1nn0 10
5 1lt10 1<10
6 1 3 4 5 declti 1<14
7 4nn 4
8 4 7 decnncl 14
9 homndx Homndx=14
10 5nn 5
11 4lt5 4<5
12 4 3 10 11 declt 14<15
13 4 10 decnncl 15
14 ccondx compndx=15
15 1 2 6 8 9 12 13 14 strle3 BasendxUHomndxHcompndx·˙Struct115