| Step | Hyp | Ref | Expression | 
						
							| 1 |  | pgindnf.1 | ⊢ Ⅎ 𝑥 𝜑 | 
						
							| 2 |  | pgindnf.2 | ⊢ Ⅎ 𝑦 𝜑 | 
						
							| 3 |  | pgindnf.3 | ⊢ ( 𝑥  =  𝑦  →  ( 𝜓  ↔  𝜒 ) ) | 
						
							| 4 |  | pgindnf.4 | ⊢ ( 𝑦  =  𝐴  →  ( 𝜒  ↔  𝜃 ) ) | 
						
							| 5 |  | pgindnf.5 | ⊢ ( 𝜑  →  ∀ 𝑥 ( ∀ 𝑦  ∈  ( ( 1st  ‘ 𝑥 )  ∪  ( 2nd  ‘ 𝑥 ) ) 𝜒  →  𝜓 ) ) | 
						
							| 6 |  | df-pg | ⊢ Pg  =  setrecs ( ( 𝑎  ∈  V  ↦  ( 𝒫  𝑎  ×  𝒫  𝑎 ) ) ) | 
						
							| 7 |  | nfv | ⊢ Ⅎ 𝑥 ∀ 𝑦  ∈  𝑧 𝜒 | 
						
							| 8 | 1 7 | nfan | ⊢ Ⅎ 𝑥 ( 𝜑  ∧  ∀ 𝑦  ∈  𝑧 𝜒 ) | 
						
							| 9 |  | pgindlem | ⊢ ( 𝑥  ∈  ( 𝒫  𝑧  ×  𝒫  𝑧 )  →  ( ( 1st  ‘ 𝑥 )  ∪  ( 2nd  ‘ 𝑥 ) )  ⊆  𝑧 ) | 
						
							| 10 | 9 | sseld | ⊢ ( 𝑥  ∈  ( 𝒫  𝑧  ×  𝒫  𝑧 )  →  ( 𝑦  ∈  ( ( 1st  ‘ 𝑥 )  ∪  ( 2nd  ‘ 𝑥 ) )  →  𝑦  ∈  𝑧 ) ) | 
						
							| 11 | 10 | imim1d | ⊢ ( 𝑥  ∈  ( 𝒫  𝑧  ×  𝒫  𝑧 )  →  ( ( 𝑦  ∈  𝑧  →  𝜒 )  →  ( 𝑦  ∈  ( ( 1st  ‘ 𝑥 )  ∪  ( 2nd  ‘ 𝑥 ) )  →  𝜒 ) ) ) | 
						
							| 12 | 11 | ralimdv2 | ⊢ ( 𝑥  ∈  ( 𝒫  𝑧  ×  𝒫  𝑧 )  →  ( ∀ 𝑦  ∈  𝑧 𝜒  →  ∀ 𝑦  ∈  ( ( 1st  ‘ 𝑥 )  ∪  ( 2nd  ‘ 𝑥 ) ) 𝜒 ) ) | 
						
							| 13 | 5 | 19.21bi | ⊢ ( 𝜑  →  ( ∀ 𝑦  ∈  ( ( 1st  ‘ 𝑥 )  ∪  ( 2nd  ‘ 𝑥 ) ) 𝜒  →  𝜓 ) ) | 
						
							| 14 | 12 13 | sylan9r | ⊢ ( ( 𝜑  ∧  𝑥  ∈  ( 𝒫  𝑧  ×  𝒫  𝑧 ) )  →  ( ∀ 𝑦  ∈  𝑧 𝜒  →  𝜓 ) ) | 
						
							| 15 | 14 | impancom | ⊢ ( ( 𝜑  ∧  ∀ 𝑦  ∈  𝑧 𝜒 )  →  ( 𝑥  ∈  ( 𝒫  𝑧  ×  𝒫  𝑧 )  →  𝜓 ) ) | 
						
							| 16 | 8 15 | ralrimi | ⊢ ( ( 𝜑  ∧  ∀ 𝑦  ∈  𝑧 𝜒 )  →  ∀ 𝑥  ∈  ( 𝒫  𝑧  ×  𝒫  𝑧 ) 𝜓 ) | 
						
							| 17 |  | vex | ⊢ 𝑧  ∈  V | 
						
							| 18 |  | pweq | ⊢ ( 𝑎  =  𝑧  →  𝒫  𝑎  =  𝒫  𝑧 ) | 
						
							| 19 | 18 | sqxpeqd | ⊢ ( 𝑎  =  𝑧  →  ( 𝒫  𝑎  ×  𝒫  𝑎 )  =  ( 𝒫  𝑧  ×  𝒫  𝑧 ) ) | 
						
							| 20 |  | eqid | ⊢ ( 𝑎  ∈  V  ↦  ( 𝒫  𝑎  ×  𝒫  𝑎 ) )  =  ( 𝑎  ∈  V  ↦  ( 𝒫  𝑎  ×  𝒫  𝑎 ) ) | 
						
							| 21 |  | vpwex | ⊢ 𝒫  𝑧  ∈  V | 
						
							| 22 | 21 21 | xpex | ⊢ ( 𝒫  𝑧  ×  𝒫  𝑧 )  ∈  V | 
						
							| 23 | 19 20 22 | fvmpt | ⊢ ( 𝑧  ∈  V  →  ( ( 𝑎  ∈  V  ↦  ( 𝒫  𝑎  ×  𝒫  𝑎 ) ) ‘ 𝑧 )  =  ( 𝒫  𝑧  ×  𝒫  𝑧 ) ) | 
						
							| 24 | 17 23 | ax-mp | ⊢ ( ( 𝑎  ∈  V  ↦  ( 𝒫  𝑎  ×  𝒫  𝑎 ) ) ‘ 𝑧 )  =  ( 𝒫  𝑧  ×  𝒫  𝑧 ) | 
						
							| 25 | 24 | eqcomi | ⊢ ( 𝒫  𝑧  ×  𝒫  𝑧 )  =  ( ( 𝑎  ∈  V  ↦  ( 𝒫  𝑎  ×  𝒫  𝑎 ) ) ‘ 𝑧 ) | 
						
							| 26 | 25 | a1i | ⊢ ( 𝑥  =  𝑦  →  ( 𝒫  𝑧  ×  𝒫  𝑧 )  =  ( ( 𝑎  ∈  V  ↦  ( 𝒫  𝑎  ×  𝒫  𝑎 ) ) ‘ 𝑧 ) ) | 
						
							| 27 | 3 26 | cbvralv2 | ⊢ ( ∀ 𝑥  ∈  ( 𝒫  𝑧  ×  𝒫  𝑧 ) 𝜓  ↔  ∀ 𝑦  ∈  ( ( 𝑎  ∈  V  ↦  ( 𝒫  𝑎  ×  𝒫  𝑎 ) ) ‘ 𝑧 ) 𝜒 ) | 
						
							| 28 | 16 27 | sylib | ⊢ ( ( 𝜑  ∧  ∀ 𝑦  ∈  𝑧 𝜒 )  →  ∀ 𝑦  ∈  ( ( 𝑎  ∈  V  ↦  ( 𝒫  𝑎  ×  𝒫  𝑎 ) ) ‘ 𝑧 ) 𝜒 ) | 
						
							| 29 | 28 | ex | ⊢ ( 𝜑  →  ( ∀ 𝑦  ∈  𝑧 𝜒  →  ∀ 𝑦  ∈  ( ( 𝑎  ∈  V  ↦  ( 𝒫  𝑎  ×  𝒫  𝑎 ) ) ‘ 𝑧 ) 𝜒 ) ) | 
						
							| 30 | 29 | alrimiv | ⊢ ( 𝜑  →  ∀ 𝑧 ( ∀ 𝑦  ∈  𝑧 𝜒  →  ∀ 𝑦  ∈  ( ( 𝑎  ∈  V  ↦  ( 𝒫  𝑎  ×  𝒫  𝑎 ) ) ‘ 𝑧 ) 𝜒 ) ) | 
						
							| 31 | 6 4 30 | setis | ⊢ ( 𝜑  →  ( 𝐴  ∈  Pg  →  𝜃 ) ) |