Metamath Proof Explorer


Theorem mndtcco

Description: The composition of the category built from a monoid is the monoid operation. (Contributed by Zhi Wang, 22-Sep-2024)

Ref Expression
Hypotheses mndtcbas.c No typesetting found for |- ( ph -> C = ( MndToCat ` M ) ) with typecode |-
mndtcbas.m φ M Mnd
mndtcbas.b φ B = Base C
mndtchom.x φ X B
mndtchom.y φ Y B
mndtcco.z φ Z B
mndtcco.o φ · ˙ = comp C
Assertion mndtcco φ X Y · ˙ Z = + M

Proof

Step Hyp Ref Expression
1 mndtcbas.c Could not format ( ph -> C = ( MndToCat ` M ) ) : No typesetting found for |- ( ph -> C = ( MndToCat ` M ) ) with typecode |-
2 mndtcbas.m φ M Mnd
3 mndtcbas.b φ B = Base C
4 mndtchom.x φ X B
5 mndtchom.y φ Y B
6 mndtcco.z φ Z B
7 mndtcco.o φ · ˙ = comp C
8 1 2 mndtcval φ C = Base ndx M Hom ndx M M Base M comp ndx M M M + M
9 catstr Base ndx M Hom ndx M M Base M comp ndx M M M + M Struct 1 15
10 ccoid comp = Slot comp ndx
11 snsstp3 comp ndx M M M + M Base ndx M Hom ndx M M Base M comp ndx M M M + M
12 snex M M M + M V
13 12 a1i φ M M M + M V
14 eqid comp C = comp C
15 8 9 10 11 13 14 strfv3 φ comp C = M M M + M
16 7 15 eqtrd φ · ˙ = M M M + M
17 1 2 3 4 mndtcob φ X = M
18 1 2 3 5 mndtcob φ Y = M
19 17 18 opeq12d φ X Y = M M
20 1 2 3 6 mndtcob φ Z = M
21 16 19 20 oveq123d φ X Y · ˙ Z = M M M M M + M M
22 df-ov M M M M M + M M = M M M + M M M M
23 df-ot M M M = M M M
24 23 fveq2i M M M + M M M M = M M M + M M M M
25 otex M M M V
26 fvex + M V
27 25 26 fvsn M M M + M M M M = + M
28 22 24 27 3eqtr2i M M M M M + M M = + M
29 21 28 eqtrdi φ X Y · ˙ Z = + M