Description: Every magma is trivially a submagma of itself. (Contributed by AV, 26-Feb-2020)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | submgmss.b | |- B = ( Base ` M )  | 
					|
| Assertion | submgmid | |- ( M e. Mgm -> B e. ( SubMgm ` M ) )  | 
				
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | submgmss.b | |- B = ( Base ` M )  | 
						|
| 2 | ssidd | |- ( M e. Mgm -> B C_ B )  | 
						|
| 3 | 1 | ressid | |- ( M e. Mgm -> ( M |`s B ) = M )  | 
						
| 4 | id | |- ( M e. Mgm -> M e. Mgm )  | 
						|
| 5 | 3 4 | eqeltrd | |- ( M e. Mgm -> ( M |`s B ) e. Mgm )  | 
						
| 6 | eqid | |- ( M |`s B ) = ( M |`s B )  | 
						|
| 7 | 1 6 | issubmgm2 | |- ( M e. Mgm -> ( B e. ( SubMgm ` M ) <-> ( B C_ B /\ ( M |`s B ) e. Mgm ) ) )  | 
						
| 8 | 2 5 7 | mpbir2and | |- ( M e. Mgm -> B e. ( SubMgm ` M ) )  |