Metamath Proof Explorer


Theorem xpcfucco2

Description: Value of composition in the binary product of categories of functors. (Contributed by Zhi Wang, 1-Oct-2025)

Ref Expression
Hypotheses xpcfuchom2.t T = B FuncCat C × c D FuncCat E
xpcfucco2.o O = comp T
xpcfucco2.f φ F M B Nat C P
xpcfucco2.g φ G N D Nat E Q
xpcfucco2.k φ K P B Nat C R
xpcfucco2.l φ L Q D Nat E S
Assertion xpcfucco2 φ K L M N P Q O R S F G = K M P comp B FuncCat C R F L N Q comp D FuncCat E S G

Proof

Step Hyp Ref Expression
1 xpcfuchom2.t T = B FuncCat C × c D FuncCat E
2 xpcfucco2.o O = comp T
3 xpcfucco2.f φ F M B Nat C P
4 xpcfucco2.g φ G N D Nat E Q
5 xpcfucco2.k φ K P B Nat C R
6 xpcfucco2.l φ L Q D Nat E S
7 eqid B FuncCat C = B FuncCat C
8 7 fucbas B Func C = Base B FuncCat C
9 eqid D FuncCat E = D FuncCat E
10 9 fucbas D Func E = Base D FuncCat E
11 eqid B Nat C = B Nat C
12 7 11 fuchom B Nat C = Hom B FuncCat C
13 eqid D Nat E = D Nat E
14 9 13 fuchom D Nat E = Hom D FuncCat E
15 11 natrcl F M B Nat C P M B Func C P B Func C
16 3 15 syl φ M B Func C P B Func C
17 16 simpld φ M B Func C
18 13 natrcl G N D Nat E Q N D Func E Q D Func E
19 4 18 syl φ N D Func E Q D Func E
20 19 simpld φ N D Func E
21 16 simprd φ P B Func C
22 19 simprd φ Q D Func E
23 eqid comp B FuncCat C = comp B FuncCat C
24 eqid comp D FuncCat E = comp D FuncCat E
25 11 natrcl K P B Nat C R P B Func C R B Func C
26 5 25 syl φ P B Func C R B Func C
27 26 simprd φ R B Func C
28 13 natrcl L Q D Nat E S Q D Func E S D Func E
29 6 28 syl φ Q D Func E S D Func E
30 29 simprd φ S D Func E
31 1 8 10 12 14 17 20 21 22 23 24 2 27 30 3 4 5 6 xpcco2 φ K L M N P Q O R S F G = K M P comp B FuncCat C R F L N Q comp D FuncCat E S G