Metamath Proof Explorer
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 |