| Step | Hyp | Ref | Expression | 
						
							| 1 |  | issubmd.b | ⊢ 𝐵  =  ( Base ‘ 𝑀 ) | 
						
							| 2 |  | issubmd.p | ⊢  +   =  ( +g ‘ 𝑀 ) | 
						
							| 3 |  | issubmd.z | ⊢  0   =  ( 0g ‘ 𝑀 ) | 
						
							| 4 |  | issubmd.m | ⊢ ( 𝜑  →  𝑀  ∈  Mnd ) | 
						
							| 5 |  | issubmd.cz | ⊢ ( 𝜑  →  𝜒 ) | 
						
							| 6 |  | issubmd.cp | ⊢ ( ( 𝜑  ∧  ( ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐵 )  ∧  ( 𝜃  ∧  𝜏 ) ) )  →  𝜂 ) | 
						
							| 7 |  | issubmd.ch | ⊢ ( 𝑧  =   0   →  ( 𝜓  ↔  𝜒 ) ) | 
						
							| 8 |  | issubmd.th | ⊢ ( 𝑧  =  𝑥  →  ( 𝜓  ↔  𝜃 ) ) | 
						
							| 9 |  | issubmd.ta | ⊢ ( 𝑧  =  𝑦  →  ( 𝜓  ↔  𝜏 ) ) | 
						
							| 10 |  | issubmd.et | ⊢ ( 𝑧  =  ( 𝑥  +  𝑦 )  →  ( 𝜓  ↔  𝜂 ) ) | 
						
							| 11 |  | ssrab2 | ⊢ { 𝑧  ∈  𝐵  ∣  𝜓 }  ⊆  𝐵 | 
						
							| 12 | 11 | a1i | ⊢ ( 𝜑  →  { 𝑧  ∈  𝐵  ∣  𝜓 }  ⊆  𝐵 ) | 
						
							| 13 | 1 3 | mndidcl | ⊢ ( 𝑀  ∈  Mnd  →   0   ∈  𝐵 ) | 
						
							| 14 | 4 13 | syl | ⊢ ( 𝜑  →   0   ∈  𝐵 ) | 
						
							| 15 | 7 14 5 | elrabd | ⊢ ( 𝜑  →   0   ∈  { 𝑧  ∈  𝐵  ∣  𝜓 } ) | 
						
							| 16 | 8 | elrab | ⊢ ( 𝑥  ∈  { 𝑧  ∈  𝐵  ∣  𝜓 }  ↔  ( 𝑥  ∈  𝐵  ∧  𝜃 ) ) | 
						
							| 17 | 9 | elrab | ⊢ ( 𝑦  ∈  { 𝑧  ∈  𝐵  ∣  𝜓 }  ↔  ( 𝑦  ∈  𝐵  ∧  𝜏 ) ) | 
						
							| 18 | 16 17 | anbi12i | ⊢ ( ( 𝑥  ∈  { 𝑧  ∈  𝐵  ∣  𝜓 }  ∧  𝑦  ∈  { 𝑧  ∈  𝐵  ∣  𝜓 } )  ↔  ( ( 𝑥  ∈  𝐵  ∧  𝜃 )  ∧  ( 𝑦  ∈  𝐵  ∧  𝜏 ) ) ) | 
						
							| 19 | 4 | adantr | ⊢ ( ( 𝜑  ∧  ( ( 𝑥  ∈  𝐵  ∧  𝜃 )  ∧  ( 𝑦  ∈  𝐵  ∧  𝜏 ) ) )  →  𝑀  ∈  Mnd ) | 
						
							| 20 |  | simprll | ⊢ ( ( 𝜑  ∧  ( ( 𝑥  ∈  𝐵  ∧  𝜃 )  ∧  ( 𝑦  ∈  𝐵  ∧  𝜏 ) ) )  →  𝑥  ∈  𝐵 ) | 
						
							| 21 |  | simprrl | ⊢ ( ( 𝜑  ∧  ( ( 𝑥  ∈  𝐵  ∧  𝜃 )  ∧  ( 𝑦  ∈  𝐵  ∧  𝜏 ) ) )  →  𝑦  ∈  𝐵 ) | 
						
							| 22 | 1 2 | mndcl | ⊢ ( ( 𝑀  ∈  Mnd  ∧  𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐵 )  →  ( 𝑥  +  𝑦 )  ∈  𝐵 ) | 
						
							| 23 | 19 20 21 22 | syl3anc | ⊢ ( ( 𝜑  ∧  ( ( 𝑥  ∈  𝐵  ∧  𝜃 )  ∧  ( 𝑦  ∈  𝐵  ∧  𝜏 ) ) )  →  ( 𝑥  +  𝑦 )  ∈  𝐵 ) | 
						
							| 24 |  | an4 | ⊢ ( ( ( 𝑥  ∈  𝐵  ∧  𝜃 )  ∧  ( 𝑦  ∈  𝐵  ∧  𝜏 ) )  ↔  ( ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐵 )  ∧  ( 𝜃  ∧  𝜏 ) ) ) | 
						
							| 25 | 24 6 | sylan2b | ⊢ ( ( 𝜑  ∧  ( ( 𝑥  ∈  𝐵  ∧  𝜃 )  ∧  ( 𝑦  ∈  𝐵  ∧  𝜏 ) ) )  →  𝜂 ) | 
						
							| 26 | 10 23 25 | elrabd | ⊢ ( ( 𝜑  ∧  ( ( 𝑥  ∈  𝐵  ∧  𝜃 )  ∧  ( 𝑦  ∈  𝐵  ∧  𝜏 ) ) )  →  ( 𝑥  +  𝑦 )  ∈  { 𝑧  ∈  𝐵  ∣  𝜓 } ) | 
						
							| 27 | 18 26 | sylan2b | ⊢ ( ( 𝜑  ∧  ( 𝑥  ∈  { 𝑧  ∈  𝐵  ∣  𝜓 }  ∧  𝑦  ∈  { 𝑧  ∈  𝐵  ∣  𝜓 } ) )  →  ( 𝑥  +  𝑦 )  ∈  { 𝑧  ∈  𝐵  ∣  𝜓 } ) | 
						
							| 28 | 27 | ralrimivva | ⊢ ( 𝜑  →  ∀ 𝑥  ∈  { 𝑧  ∈  𝐵  ∣  𝜓 } ∀ 𝑦  ∈  { 𝑧  ∈  𝐵  ∣  𝜓 } ( 𝑥  +  𝑦 )  ∈  { 𝑧  ∈  𝐵  ∣  𝜓 } ) | 
						
							| 29 | 1 3 2 | issubm | ⊢ ( 𝑀  ∈  Mnd  →  ( { 𝑧  ∈  𝐵  ∣  𝜓 }  ∈  ( SubMnd ‘ 𝑀 )  ↔  ( { 𝑧  ∈  𝐵  ∣  𝜓 }  ⊆  𝐵  ∧   0   ∈  { 𝑧  ∈  𝐵  ∣  𝜓 }  ∧  ∀ 𝑥  ∈  { 𝑧  ∈  𝐵  ∣  𝜓 } ∀ 𝑦  ∈  { 𝑧  ∈  𝐵  ∣  𝜓 } ( 𝑥  +  𝑦 )  ∈  { 𝑧  ∈  𝐵  ∣  𝜓 } ) ) ) | 
						
							| 30 | 4 29 | syl | ⊢ ( 𝜑  →  ( { 𝑧  ∈  𝐵  ∣  𝜓 }  ∈  ( SubMnd ‘ 𝑀 )  ↔  ( { 𝑧  ∈  𝐵  ∣  𝜓 }  ⊆  𝐵  ∧   0   ∈  { 𝑧  ∈  𝐵  ∣  𝜓 }  ∧  ∀ 𝑥  ∈  { 𝑧  ∈  𝐵  ∣  𝜓 } ∀ 𝑦  ∈  { 𝑧  ∈  𝐵  ∣  𝜓 } ( 𝑥  +  𝑦 )  ∈  { 𝑧  ∈  𝐵  ∣  𝜓 } ) ) ) | 
						
							| 31 | 12 15 28 30 | mpbir3and | ⊢ ( 𝜑  →  { 𝑧  ∈  𝐵  ∣  𝜓 }  ∈  ( SubMnd ‘ 𝑀 ) ) |