| Step | Hyp | Ref | Expression | 
						
							| 1 |  | imasmnd.u | ⊢ ( 𝜑  →  𝑈  =  ( 𝐹  “s  𝑅 ) ) | 
						
							| 2 |  | imasmnd.v | ⊢ ( 𝜑  →  𝑉  =  ( Base ‘ 𝑅 ) ) | 
						
							| 3 |  | imasmnd.p | ⊢  +   =  ( +g ‘ 𝑅 ) | 
						
							| 4 |  | imasmnd.f | ⊢ ( 𝜑  →  𝐹 : 𝑉 –onto→ 𝐵 ) | 
						
							| 5 |  | imasmnd.e | ⊢ ( ( 𝜑  ∧  ( 𝑎  ∈  𝑉  ∧  𝑏  ∈  𝑉 )  ∧  ( 𝑝  ∈  𝑉  ∧  𝑞  ∈  𝑉 ) )  →  ( ( ( 𝐹 ‘ 𝑎 )  =  ( 𝐹 ‘ 𝑝 )  ∧  ( 𝐹 ‘ 𝑏 )  =  ( 𝐹 ‘ 𝑞 ) )  →  ( 𝐹 ‘ ( 𝑎  +  𝑏 ) )  =  ( 𝐹 ‘ ( 𝑝  +  𝑞 ) ) ) ) | 
						
							| 6 |  | imasmnd.r | ⊢ ( 𝜑  →  𝑅  ∈  Mnd ) | 
						
							| 7 |  | imasmnd.z | ⊢  0   =  ( 0g ‘ 𝑅 ) | 
						
							| 8 | 6 | 3ad2ant1 | ⊢ ( ( 𝜑  ∧  𝑥  ∈  𝑉  ∧  𝑦  ∈  𝑉 )  →  𝑅  ∈  Mnd ) | 
						
							| 9 |  | simp2 | ⊢ ( ( 𝜑  ∧  𝑥  ∈  𝑉  ∧  𝑦  ∈  𝑉 )  →  𝑥  ∈  𝑉 ) | 
						
							| 10 | 2 | 3ad2ant1 | ⊢ ( ( 𝜑  ∧  𝑥  ∈  𝑉  ∧  𝑦  ∈  𝑉 )  →  𝑉  =  ( Base ‘ 𝑅 ) ) | 
						
							| 11 | 9 10 | eleqtrd | ⊢ ( ( 𝜑  ∧  𝑥  ∈  𝑉  ∧  𝑦  ∈  𝑉 )  →  𝑥  ∈  ( Base ‘ 𝑅 ) ) | 
						
							| 12 |  | simp3 | ⊢ ( ( 𝜑  ∧  𝑥  ∈  𝑉  ∧  𝑦  ∈  𝑉 )  →  𝑦  ∈  𝑉 ) | 
						
							| 13 | 12 10 | eleqtrd | ⊢ ( ( 𝜑  ∧  𝑥  ∈  𝑉  ∧  𝑦  ∈  𝑉 )  →  𝑦  ∈  ( Base ‘ 𝑅 ) ) | 
						
							| 14 |  | eqid | ⊢ ( Base ‘ 𝑅 )  =  ( Base ‘ 𝑅 ) | 
						
							| 15 | 14 3 | mndcl | ⊢ ( ( 𝑅  ∈  Mnd  ∧  𝑥  ∈  ( Base ‘ 𝑅 )  ∧  𝑦  ∈  ( Base ‘ 𝑅 ) )  →  ( 𝑥  +  𝑦 )  ∈  ( Base ‘ 𝑅 ) ) | 
						
							| 16 | 8 11 13 15 | syl3anc | ⊢ ( ( 𝜑  ∧  𝑥  ∈  𝑉  ∧  𝑦  ∈  𝑉 )  →  ( 𝑥  +  𝑦 )  ∈  ( Base ‘ 𝑅 ) ) | 
						
							| 17 | 16 10 | eleqtrrd | ⊢ ( ( 𝜑  ∧  𝑥  ∈  𝑉  ∧  𝑦  ∈  𝑉 )  →  ( 𝑥  +  𝑦 )  ∈  𝑉 ) | 
						
							| 18 | 6 | adantr | ⊢ ( ( 𝜑  ∧  ( 𝑥  ∈  𝑉  ∧  𝑦  ∈  𝑉  ∧  𝑧  ∈  𝑉 ) )  →  𝑅  ∈  Mnd ) | 
						
							| 19 | 11 | 3adant3r3 | ⊢ ( ( 𝜑  ∧  ( 𝑥  ∈  𝑉  ∧  𝑦  ∈  𝑉  ∧  𝑧  ∈  𝑉 ) )  →  𝑥  ∈  ( Base ‘ 𝑅 ) ) | 
						
							| 20 | 13 | 3adant3r3 | ⊢ ( ( 𝜑  ∧  ( 𝑥  ∈  𝑉  ∧  𝑦  ∈  𝑉  ∧  𝑧  ∈  𝑉 ) )  →  𝑦  ∈  ( Base ‘ 𝑅 ) ) | 
						
							| 21 |  | simpr3 | ⊢ ( ( 𝜑  ∧  ( 𝑥  ∈  𝑉  ∧  𝑦  ∈  𝑉  ∧  𝑧  ∈  𝑉 ) )  →  𝑧  ∈  𝑉 ) | 
						
							| 22 | 2 | adantr | ⊢ ( ( 𝜑  ∧  ( 𝑥  ∈  𝑉  ∧  𝑦  ∈  𝑉  ∧  𝑧  ∈  𝑉 ) )  →  𝑉  =  ( Base ‘ 𝑅 ) ) | 
						
							| 23 | 21 22 | eleqtrd | ⊢ ( ( 𝜑  ∧  ( 𝑥  ∈  𝑉  ∧  𝑦  ∈  𝑉  ∧  𝑧  ∈  𝑉 ) )  →  𝑧  ∈  ( Base ‘ 𝑅 ) ) | 
						
							| 24 | 14 3 | mndass | ⊢ ( ( 𝑅  ∈  Mnd  ∧  ( 𝑥  ∈  ( Base ‘ 𝑅 )  ∧  𝑦  ∈  ( Base ‘ 𝑅 )  ∧  𝑧  ∈  ( Base ‘ 𝑅 ) ) )  →  ( ( 𝑥  +  𝑦 )  +  𝑧 )  =  ( 𝑥  +  ( 𝑦  +  𝑧 ) ) ) | 
						
							| 25 | 18 19 20 23 24 | syl13anc | ⊢ ( ( 𝜑  ∧  ( 𝑥  ∈  𝑉  ∧  𝑦  ∈  𝑉  ∧  𝑧  ∈  𝑉 ) )  →  ( ( 𝑥  +  𝑦 )  +  𝑧 )  =  ( 𝑥  +  ( 𝑦  +  𝑧 ) ) ) | 
						
							| 26 | 25 | fveq2d | ⊢ ( ( 𝜑  ∧  ( 𝑥  ∈  𝑉  ∧  𝑦  ∈  𝑉  ∧  𝑧  ∈  𝑉 ) )  →  ( 𝐹 ‘ ( ( 𝑥  +  𝑦 )  +  𝑧 ) )  =  ( 𝐹 ‘ ( 𝑥  +  ( 𝑦  +  𝑧 ) ) ) ) | 
						
							| 27 | 14 7 | mndidcl | ⊢ ( 𝑅  ∈  Mnd  →   0   ∈  ( Base ‘ 𝑅 ) ) | 
						
							| 28 | 6 27 | syl | ⊢ ( 𝜑  →   0   ∈  ( Base ‘ 𝑅 ) ) | 
						
							| 29 | 28 2 | eleqtrrd | ⊢ ( 𝜑  →   0   ∈  𝑉 ) | 
						
							| 30 | 2 | eleq2d | ⊢ ( 𝜑  →  ( 𝑥  ∈  𝑉  ↔  𝑥  ∈  ( Base ‘ 𝑅 ) ) ) | 
						
							| 31 | 30 | biimpa | ⊢ ( ( 𝜑  ∧  𝑥  ∈  𝑉 )  →  𝑥  ∈  ( Base ‘ 𝑅 ) ) | 
						
							| 32 | 14 3 7 | mndlid | ⊢ ( ( 𝑅  ∈  Mnd  ∧  𝑥  ∈  ( Base ‘ 𝑅 ) )  →  (  0   +  𝑥 )  =  𝑥 ) | 
						
							| 33 | 6 31 32 | syl2an2r | ⊢ ( ( 𝜑  ∧  𝑥  ∈  𝑉 )  →  (  0   +  𝑥 )  =  𝑥 ) | 
						
							| 34 | 33 | fveq2d | ⊢ ( ( 𝜑  ∧  𝑥  ∈  𝑉 )  →  ( 𝐹 ‘ (  0   +  𝑥 ) )  =  ( 𝐹 ‘ 𝑥 ) ) | 
						
							| 35 | 14 3 7 | mndrid | ⊢ ( ( 𝑅  ∈  Mnd  ∧  𝑥  ∈  ( Base ‘ 𝑅 ) )  →  ( 𝑥  +   0  )  =  𝑥 ) | 
						
							| 36 | 6 31 35 | syl2an2r | ⊢ ( ( 𝜑  ∧  𝑥  ∈  𝑉 )  →  ( 𝑥  +   0  )  =  𝑥 ) | 
						
							| 37 | 36 | fveq2d | ⊢ ( ( 𝜑  ∧  𝑥  ∈  𝑉 )  →  ( 𝐹 ‘ ( 𝑥  +   0  ) )  =  ( 𝐹 ‘ 𝑥 ) ) | 
						
							| 38 | 1 2 3 4 5 6 17 26 29 34 37 | imasmnd2 | ⊢ ( 𝜑  →  ( 𝑈  ∈  Mnd  ∧  ( 𝐹 ‘  0  )  =  ( 0g ‘ 𝑈 ) ) ) |