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Description: The monoid of endofunctions on a class A is a magma. (Contributed by AV, 28-Jan-2024)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | efmndmgm.g | ⊢ 𝐺 = ( EndoFMnd ‘ 𝐴 ) | |
| Assertion | efmndmgm | ⊢ 𝐺 ∈ Mgm |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | efmndmgm.g | ⊢ 𝐺 = ( EndoFMnd ‘ 𝐴 ) | |
| 2 | eqid | ⊢ ( Base ‘ 𝐺 ) = ( Base ‘ 𝐺 ) | |
| 3 | eqid | ⊢ ( +g ‘ 𝐺 ) = ( +g ‘ 𝐺 ) | |
| 4 | 1 2 3 | efmndcl | ⊢ ( ( 𝑓 ∈ ( Base ‘ 𝐺 ) ∧ 𝑔 ∈ ( Base ‘ 𝐺 ) ) → ( 𝑓 ( +g ‘ 𝐺 ) 𝑔 ) ∈ ( Base ‘ 𝐺 ) ) |
| 5 | 4 | rgen2 | ⊢ ∀ 𝑓 ∈ ( Base ‘ 𝐺 ) ∀ 𝑔 ∈ ( Base ‘ 𝐺 ) ( 𝑓 ( +g ‘ 𝐺 ) 𝑔 ) ∈ ( Base ‘ 𝐺 ) |
| 6 | 1 | fvexi | ⊢ 𝐺 ∈ V |
| 7 | 2 3 | ismgm | ⊢ ( 𝐺 ∈ V → ( 𝐺 ∈ Mgm ↔ ∀ 𝑓 ∈ ( Base ‘ 𝐺 ) ∀ 𝑔 ∈ ( Base ‘ 𝐺 ) ( 𝑓 ( +g ‘ 𝐺 ) 𝑔 ) ∈ ( Base ‘ 𝐺 ) ) ) |
| 8 | 6 7 | ax-mp | ⊢ ( 𝐺 ∈ Mgm ↔ ∀ 𝑓 ∈ ( Base ‘ 𝐺 ) ∀ 𝑔 ∈ ( Base ‘ 𝐺 ) ( 𝑓 ( +g ‘ 𝐺 ) 𝑔 ) ∈ ( Base ‘ 𝐺 ) ) |
| 9 | 5 8 | mpbir | ⊢ 𝐺 ∈ Mgm |