| Step | Hyp | Ref | Expression | 
						
							| 1 |  | prjspner01.e | ⊢  ∼   =  { 〈 𝑥 ,  𝑦 〉  ∣  ( ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐵 )  ∧  ∃ 𝑙  ∈  𝑆 𝑥  =  ( 𝑙  ·  𝑦 ) ) } | 
						
							| 2 |  | prjspner01.f | ⊢ 𝐹  =  ( 𝑏  ∈  𝐵  ↦  if ( ( 𝑏 ‘ 0 )  =   0  ,  𝑏 ,  ( ( 𝐼 ‘ ( 𝑏 ‘ 0 ) )  ·  𝑏 ) ) ) | 
						
							| 3 |  | prjspner01.b | ⊢ 𝐵  =  ( ( Base ‘ 𝑊 )  ∖  { ( 0g ‘ 𝑊 ) } ) | 
						
							| 4 |  | prjspner01.w | ⊢ 𝑊  =  ( 𝐾  freeLMod  ( 0 ... 𝑁 ) ) | 
						
							| 5 |  | prjspner01.t | ⊢  ·   =  (  ·𝑠  ‘ 𝑊 ) | 
						
							| 6 |  | prjspner01.s | ⊢ 𝑆  =  ( Base ‘ 𝐾 ) | 
						
							| 7 |  | prjspner01.0 | ⊢  0   =  ( 0g ‘ 𝐾 ) | 
						
							| 8 |  | prjspner01.i | ⊢ 𝐼  =  ( invr ‘ 𝐾 ) | 
						
							| 9 |  | prjspner01.k | ⊢ ( 𝜑  →  𝐾  ∈  DivRing ) | 
						
							| 10 |  | prjspner01.n | ⊢ ( 𝜑  →  𝑁  ∈  ℕ0 ) | 
						
							| 11 |  | prjspner01.x | ⊢ ( 𝜑  →  𝑋  ∈  𝐵 ) | 
						
							| 12 | 1 4 3 6 5 9 | prjspner | ⊢ ( 𝜑  →   ∼   Er  𝐵 ) | 
						
							| 13 | 12 11 | erref | ⊢ ( 𝜑  →  𝑋  ∼  𝑋 ) | 
						
							| 14 | 13 | adantr | ⊢ ( ( 𝜑  ∧  ( 𝑋 ‘ 0 )  =   0  )  →  𝑋  ∼  𝑋 ) | 
						
							| 15 | 12 | adantr | ⊢ ( ( 𝜑  ∧  ¬  ( 𝑋 ‘ 0 )  =   0  )  →   ∼   Er  𝐵 ) | 
						
							| 16 | 9 | adantr | ⊢ ( ( 𝜑  ∧  ¬  ( 𝑋 ‘ 0 )  =   0  )  →  𝐾  ∈  DivRing ) | 
						
							| 17 | 11 | adantr | ⊢ ( ( 𝜑  ∧  ¬  ( 𝑋 ‘ 0 )  =   0  )  →  𝑋  ∈  𝐵 ) | 
						
							| 18 |  | ovexd | ⊢ ( 𝜑  →  ( 0 ... 𝑁 )  ∈  V ) | 
						
							| 19 | 11 3 | eleqtrdi | ⊢ ( 𝜑  →  𝑋  ∈  ( ( Base ‘ 𝑊 )  ∖  { ( 0g ‘ 𝑊 ) } ) ) | 
						
							| 20 | 19 | eldifad | ⊢ ( 𝜑  →  𝑋  ∈  ( Base ‘ 𝑊 ) ) | 
						
							| 21 |  | eqid | ⊢ ( Base ‘ 𝑊 )  =  ( Base ‘ 𝑊 ) | 
						
							| 22 | 4 6 21 | frlmbasf | ⊢ ( ( ( 0 ... 𝑁 )  ∈  V  ∧  𝑋  ∈  ( Base ‘ 𝑊 ) )  →  𝑋 : ( 0 ... 𝑁 ) ⟶ 𝑆 ) | 
						
							| 23 | 18 20 22 | syl2anc | ⊢ ( 𝜑  →  𝑋 : ( 0 ... 𝑁 ) ⟶ 𝑆 ) | 
						
							| 24 |  | 0elfz | ⊢ ( 𝑁  ∈  ℕ0  →  0  ∈  ( 0 ... 𝑁 ) ) | 
						
							| 25 | 10 24 | syl | ⊢ ( 𝜑  →  0  ∈  ( 0 ... 𝑁 ) ) | 
						
							| 26 | 23 25 | ffvelcdmd | ⊢ ( 𝜑  →  ( 𝑋 ‘ 0 )  ∈  𝑆 ) | 
						
							| 27 |  | neqne | ⊢ ( ¬  ( 𝑋 ‘ 0 )  =   0   →  ( 𝑋 ‘ 0 )  ≠   0  ) | 
						
							| 28 | 6 7 8 | drnginvrcl | ⊢ ( ( 𝐾  ∈  DivRing  ∧  ( 𝑋 ‘ 0 )  ∈  𝑆  ∧  ( 𝑋 ‘ 0 )  ≠   0  )  →  ( 𝐼 ‘ ( 𝑋 ‘ 0 ) )  ∈  𝑆 ) | 
						
							| 29 | 9 26 27 28 | syl2an3an | ⊢ ( ( 𝜑  ∧  ¬  ( 𝑋 ‘ 0 )  =   0  )  →  ( 𝐼 ‘ ( 𝑋 ‘ 0 ) )  ∈  𝑆 ) | 
						
							| 30 | 6 7 8 | drnginvrn0 | ⊢ ( ( 𝐾  ∈  DivRing  ∧  ( 𝑋 ‘ 0 )  ∈  𝑆  ∧  ( 𝑋 ‘ 0 )  ≠   0  )  →  ( 𝐼 ‘ ( 𝑋 ‘ 0 ) )  ≠   0  ) | 
						
							| 31 | 9 26 27 30 | syl2an3an | ⊢ ( ( 𝜑  ∧  ¬  ( 𝑋 ‘ 0 )  =   0  )  →  ( 𝐼 ‘ ( 𝑋 ‘ 0 ) )  ≠   0  ) | 
						
							| 32 | 1 4 3 6 5 7 16 17 29 31 | prjspnvs | ⊢ ( ( 𝜑  ∧  ¬  ( 𝑋 ‘ 0 )  =   0  )  →  ( ( 𝐼 ‘ ( 𝑋 ‘ 0 ) )  ·  𝑋 )  ∼  𝑋 ) | 
						
							| 33 | 15 32 | ersym | ⊢ ( ( 𝜑  ∧  ¬  ( 𝑋 ‘ 0 )  =   0  )  →  𝑋  ∼  ( ( 𝐼 ‘ ( 𝑋 ‘ 0 ) )  ·  𝑋 ) ) | 
						
							| 34 | 14 33 | ifpimpda | ⊢ ( 𝜑  →  if- ( ( 𝑋 ‘ 0 )  =   0  ,  𝑋  ∼  𝑋 ,  𝑋  ∼  ( ( 𝐼 ‘ ( 𝑋 ‘ 0 ) )  ·  𝑋 ) ) ) | 
						
							| 35 |  | brif2 | ⊢ ( 𝑋  ∼  if ( ( 𝑋 ‘ 0 )  =   0  ,  𝑋 ,  ( ( 𝐼 ‘ ( 𝑋 ‘ 0 ) )  ·  𝑋 ) )  ↔  if- ( ( 𝑋 ‘ 0 )  =   0  ,  𝑋  ∼  𝑋 ,  𝑋  ∼  ( ( 𝐼 ‘ ( 𝑋 ‘ 0 ) )  ·  𝑋 ) ) ) | 
						
							| 36 | 34 35 | sylibr | ⊢ ( 𝜑  →  𝑋  ∼  if ( ( 𝑋 ‘ 0 )  =   0  ,  𝑋 ,  ( ( 𝐼 ‘ ( 𝑋 ‘ 0 ) )  ·  𝑋 ) ) ) | 
						
							| 37 |  | fveq1 | ⊢ ( 𝑏  =  𝑋  →  ( 𝑏 ‘ 0 )  =  ( 𝑋 ‘ 0 ) ) | 
						
							| 38 | 37 | eqeq1d | ⊢ ( 𝑏  =  𝑋  →  ( ( 𝑏 ‘ 0 )  =   0   ↔  ( 𝑋 ‘ 0 )  =   0  ) ) | 
						
							| 39 |  | id | ⊢ ( 𝑏  =  𝑋  →  𝑏  =  𝑋 ) | 
						
							| 40 | 37 | fveq2d | ⊢ ( 𝑏  =  𝑋  →  ( 𝐼 ‘ ( 𝑏 ‘ 0 ) )  =  ( 𝐼 ‘ ( 𝑋 ‘ 0 ) ) ) | 
						
							| 41 | 40 39 | oveq12d | ⊢ ( 𝑏  =  𝑋  →  ( ( 𝐼 ‘ ( 𝑏 ‘ 0 ) )  ·  𝑏 )  =  ( ( 𝐼 ‘ ( 𝑋 ‘ 0 ) )  ·  𝑋 ) ) | 
						
							| 42 | 38 39 41 | ifbieq12d | ⊢ ( 𝑏  =  𝑋  →  if ( ( 𝑏 ‘ 0 )  =   0  ,  𝑏 ,  ( ( 𝐼 ‘ ( 𝑏 ‘ 0 ) )  ·  𝑏 ) )  =  if ( ( 𝑋 ‘ 0 )  =   0  ,  𝑋 ,  ( ( 𝐼 ‘ ( 𝑋 ‘ 0 ) )  ·  𝑋 ) ) ) | 
						
							| 43 |  | ovexd | ⊢ ( 𝜑  →  ( ( 𝐼 ‘ ( 𝑋 ‘ 0 ) )  ·  𝑋 )  ∈  V ) | 
						
							| 44 | 11 43 | ifexd | ⊢ ( 𝜑  →  if ( ( 𝑋 ‘ 0 )  =   0  ,  𝑋 ,  ( ( 𝐼 ‘ ( 𝑋 ‘ 0 ) )  ·  𝑋 ) )  ∈  V ) | 
						
							| 45 | 2 42 11 44 | fvmptd3 | ⊢ ( 𝜑  →  ( 𝐹 ‘ 𝑋 )  =  if ( ( 𝑋 ‘ 0 )  =   0  ,  𝑋 ,  ( ( 𝐼 ‘ ( 𝑋 ‘ 0 ) )  ·  𝑋 ) ) ) | 
						
							| 46 | 36 45 | breqtrrd | ⊢ ( 𝜑  →  𝑋  ∼  ( 𝐹 ‘ 𝑋 ) ) |