Metamath Proof Explorer


Definition df-sgrp2

Description: Asemigroup is a magma with an associative operation. Definition in section II.1 of Bruck p. 23, or of an "associative magma" in definition 5 of BourbakiAlg1 p. 4, or of a semigroup in section 1.3 of Hall p. 7. (Contributed by AV, 6-Jan-2020)

Ref Expression
Assertion df-sgrp2 SGrpALT = { 𝑔 ∈ MgmALT ∣ ( +g ‘ 𝑔 ) assLaw ( Base ‘ 𝑔 ) }

Detailed syntax breakdown

Step Hyp Ref Expression
0 csgrp2 ⊢ SGrpALT
1 vg ⊢ 𝑔
2 cmgm2 ⊢ MgmALT
3 cplusg ⊢ +g
4 1 cv ⊢ 𝑔
5 4 3 cfv ⊢ ( +g ‘ 𝑔 )
6 casslaw ⊢ assLaw
7 cbs ⊢ Base
8 4 7 cfv ⊢ ( Base ‘ 𝑔 )
9 5 8 6 wbr ⊢ ( +g ‘ 𝑔 ) assLaw ( Base ‘ 𝑔 )
10 9 1 2 crab ⊢ { 𝑔 ∈ MgmALT ∣ ( +g ‘ 𝑔 ) assLaw ( Base ‘ 𝑔 ) }
11 0 10 wceq ⊢ SGrpALT = { 𝑔 ∈ MgmALT ∣ ( +g ‘ 𝑔 ) assLaw ( Base ‘ 𝑔 ) }