Metamath Proof Explorer


Theorem sgrpssmgm

Description: The class of all semigroups is a proper subclass of the class of all magmas. (Contributed by AV, 29-Jan-2020)

Ref Expression
Assertion sgrpssmgm ⊢ Smgrp ⊂ Mgm

Proof

Step Hyp Ref Expression
1 sgrpmgm ⊢ x ∈ Smgrp → x ∈ Mgm
2 1 ssriv ⊢ Smgrp ⊆ Mgm
3 mgmnsgrpex ⊢ ∃ x ∈ Mgm x ∉ Smgrp
4 ssexnelpss ⊢ Smgrp ⊆ Mgm ∧ ∃ x ∈ Mgm x ∉ Smgrp → Smgrp ⊂ Mgm
5 2 3 4 mp2an ⊢ Smgrp ⊂ Mgm