Metamath Proof Explorer


Theorem copissgrp

Description: A structure with a constant group addition operation is a semigroup if the constant is contained in the base set. (Contributed by AV, 16-Feb-2020)

Ref Expression
Hypotheses copissgrp.b 𝐵 = ( Base ‘ 𝑀 )
copissgrp.p ( +g𝑀 ) = ( 𝑥𝐵 , 𝑦𝐵𝐶 )
copissgrp.n ( 𝜑𝐵 ≠ ∅ )
copissgrp.c ( 𝜑𝐶𝐵 )
Assertion copissgrp ( 𝜑𝑀 ∈ Smgrp )

Proof

Step Hyp Ref Expression
1 copissgrp.b 𝐵 = ( Base ‘ 𝑀 )
2 copissgrp.p ( +g𝑀 ) = ( 𝑥𝐵 , 𝑦𝐵𝐶 )
3 copissgrp.n ( 𝜑𝐵 ≠ ∅ )
4 copissgrp.c ( 𝜑𝐶𝐵 )
5 4 adantr ( ( 𝜑 ∧ ( 𝑥𝐵𝑦𝐵 ) ) → 𝐶𝐵 )
6 1 2 3 5 opmpoismgm ( 𝜑𝑀 ∈ Mgm )
7 eqidd ( ( 𝐶𝐵 ∧ ( 𝑎𝐵𝑏𝐵𝑐𝐵 ) ) → ( 𝑥𝐵 , 𝑦𝐵𝐶 ) = ( 𝑥𝐵 , 𝑦𝐵𝐶 ) )
8 eqidd ( ( ( 𝐶𝐵 ∧ ( 𝑎𝐵𝑏𝐵𝑐𝐵 ) ) ∧ ( 𝑥 = 𝐶𝑦 = 𝑐 ) ) → 𝐶 = 𝐶 )
9 simpl ( ( 𝐶𝐵 ∧ ( 𝑎𝐵𝑏𝐵𝑐𝐵 ) ) → 𝐶𝐵 )
10 simpr3 ( ( 𝐶𝐵 ∧ ( 𝑎𝐵𝑏𝐵𝑐𝐵 ) ) → 𝑐𝐵 )
11 7 8 9 10 9 ovmpod ( ( 𝐶𝐵 ∧ ( 𝑎𝐵𝑏𝐵𝑐𝐵 ) ) → ( 𝐶 ( 𝑥𝐵 , 𝑦𝐵𝐶 ) 𝑐 ) = 𝐶 )
12 eqidd ( ( ( 𝐶𝐵 ∧ ( 𝑎𝐵𝑏𝐵𝑐𝐵 ) ) ∧ ( 𝑥 = 𝑎𝑦 = 𝐶 ) ) → 𝐶 = 𝐶 )
13 simpr1 ( ( 𝐶𝐵 ∧ ( 𝑎𝐵𝑏𝐵𝑐𝐵 ) ) → 𝑎𝐵 )
14 7 12 13 9 9 ovmpod ( ( 𝐶𝐵 ∧ ( 𝑎𝐵𝑏𝐵𝑐𝐵 ) ) → ( 𝑎 ( 𝑥𝐵 , 𝑦𝐵𝐶 ) 𝐶 ) = 𝐶 )
15 11 14 eqtr4d ( ( 𝐶𝐵 ∧ ( 𝑎𝐵𝑏𝐵𝑐𝐵 ) ) → ( 𝐶 ( 𝑥𝐵 , 𝑦𝐵𝐶 ) 𝑐 ) = ( 𝑎 ( 𝑥𝐵 , 𝑦𝐵𝐶 ) 𝐶 ) )
16 4 15 sylan ( ( 𝜑 ∧ ( 𝑎𝐵𝑏𝐵𝑐𝐵 ) ) → ( 𝐶 ( 𝑥𝐵 , 𝑦𝐵𝐶 ) 𝑐 ) = ( 𝑎 ( 𝑥𝐵 , 𝑦𝐵𝐶 ) 𝐶 ) )
17 eqidd ( ( 𝜑 ∧ ( 𝑎𝐵𝑏𝐵𝑐𝐵 ) ) → ( 𝑥𝐵 , 𝑦𝐵𝐶 ) = ( 𝑥𝐵 , 𝑦𝐵𝐶 ) )
18 eqidd ( ( ( 𝜑 ∧ ( 𝑎𝐵𝑏𝐵𝑐𝐵 ) ) ∧ ( 𝑥 = 𝑎𝑦 = 𝑏 ) ) → 𝐶 = 𝐶 )
19 simpr1 ( ( 𝜑 ∧ ( 𝑎𝐵𝑏𝐵𝑐𝐵 ) ) → 𝑎𝐵 )
20 simpr2 ( ( 𝜑 ∧ ( 𝑎𝐵𝑏𝐵𝑐𝐵 ) ) → 𝑏𝐵 )
21 4 adantr ( ( 𝜑 ∧ ( 𝑎𝐵𝑏𝐵𝑐𝐵 ) ) → 𝐶𝐵 )
22 17 18 19 20 21 ovmpod ( ( 𝜑 ∧ ( 𝑎𝐵𝑏𝐵𝑐𝐵 ) ) → ( 𝑎 ( 𝑥𝐵 , 𝑦𝐵𝐶 ) 𝑏 ) = 𝐶 )
23 22 oveq1d ( ( 𝜑 ∧ ( 𝑎𝐵𝑏𝐵𝑐𝐵 ) ) → ( ( 𝑎 ( 𝑥𝐵 , 𝑦𝐵𝐶 ) 𝑏 ) ( 𝑥𝐵 , 𝑦𝐵𝐶 ) 𝑐 ) = ( 𝐶 ( 𝑥𝐵 , 𝑦𝐵𝐶 ) 𝑐 ) )
24 eqidd ( ( ( 𝜑 ∧ ( 𝑎𝐵𝑏𝐵𝑐𝐵 ) ) ∧ ( 𝑥 = 𝑏𝑦 = 𝑐 ) ) → 𝐶 = 𝐶 )
25 simpr3 ( ( 𝜑 ∧ ( 𝑎𝐵𝑏𝐵𝑐𝐵 ) ) → 𝑐𝐵 )
26 17 24 20 25 21 ovmpod ( ( 𝜑 ∧ ( 𝑎𝐵𝑏𝐵𝑐𝐵 ) ) → ( 𝑏 ( 𝑥𝐵 , 𝑦𝐵𝐶 ) 𝑐 ) = 𝐶 )
27 26 oveq2d ( ( 𝜑 ∧ ( 𝑎𝐵𝑏𝐵𝑐𝐵 ) ) → ( 𝑎 ( 𝑥𝐵 , 𝑦𝐵𝐶 ) ( 𝑏 ( 𝑥𝐵 , 𝑦𝐵𝐶 ) 𝑐 ) ) = ( 𝑎 ( 𝑥𝐵 , 𝑦𝐵𝐶 ) 𝐶 ) )
28 16 23 27 3eqtr4d ( ( 𝜑 ∧ ( 𝑎𝐵𝑏𝐵𝑐𝐵 ) ) → ( ( 𝑎 ( 𝑥𝐵 , 𝑦𝐵𝐶 ) 𝑏 ) ( 𝑥𝐵 , 𝑦𝐵𝐶 ) 𝑐 ) = ( 𝑎 ( 𝑥𝐵 , 𝑦𝐵𝐶 ) ( 𝑏 ( 𝑥𝐵 , 𝑦𝐵𝐶 ) 𝑐 ) ) )
29 28 ralrimivvva ( 𝜑 → ∀ 𝑎𝐵𝑏𝐵𝑐𝐵 ( ( 𝑎 ( 𝑥𝐵 , 𝑦𝐵𝐶 ) 𝑏 ) ( 𝑥𝐵 , 𝑦𝐵𝐶 ) 𝑐 ) = ( 𝑎 ( 𝑥𝐵 , 𝑦𝐵𝐶 ) ( 𝑏 ( 𝑥𝐵 , 𝑦𝐵𝐶 ) 𝑐 ) ) )
30 2 eqcomi ( 𝑥𝐵 , 𝑦𝐵𝐶 ) = ( +g𝑀 )
31 1 30 issgrp ( 𝑀 ∈ Smgrp ↔ ( 𝑀 ∈ Mgm ∧ ∀ 𝑎𝐵𝑏𝐵𝑐𝐵 ( ( 𝑎 ( 𝑥𝐵 , 𝑦𝐵𝐶 ) 𝑏 ) ( 𝑥𝐵 , 𝑦𝐵𝐶 ) 𝑐 ) = ( 𝑎 ( 𝑥𝐵 , 𝑦𝐵𝐶 ) ( 𝑏 ( 𝑥𝐵 , 𝑦𝐵𝐶 ) 𝑐 ) ) ) )
32 6 29 31 sylanbrc ( 𝜑𝑀 ∈ Smgrp )