| Step | Hyp | Ref | Expression | 
						
							| 1 |  | psrbaspropd.e | ⊢ ( 𝜑  →  ( Base ‘ 𝑅 )  =  ( Base ‘ 𝑆 ) ) | 
						
							| 2 |  | eqid | ⊢ ( 𝐼  mPwSer  𝑅 )  =  ( 𝐼  mPwSer  𝑅 ) | 
						
							| 3 |  | eqid | ⊢ ( Base ‘ 𝑅 )  =  ( Base ‘ 𝑅 ) | 
						
							| 4 |  | eqid | ⊢ { 𝑎  ∈  ( ℕ0  ↑m  𝐼 )  ∣  ( ◡ 𝑎  “  ℕ )  ∈  Fin }  =  { 𝑎  ∈  ( ℕ0  ↑m  𝐼 )  ∣  ( ◡ 𝑎  “  ℕ )  ∈  Fin } | 
						
							| 5 |  | eqid | ⊢ ( Base ‘ ( 𝐼  mPwSer  𝑅 ) )  =  ( Base ‘ ( 𝐼  mPwSer  𝑅 ) ) | 
						
							| 6 |  | simpr | ⊢ ( ( 𝜑  ∧  𝐼  ∈  V )  →  𝐼  ∈  V ) | 
						
							| 7 | 2 3 4 5 6 | psrbas | ⊢ ( ( 𝜑  ∧  𝐼  ∈  V )  →  ( Base ‘ ( 𝐼  mPwSer  𝑅 ) )  =  ( ( Base ‘ 𝑅 )  ↑m  { 𝑎  ∈  ( ℕ0  ↑m  𝐼 )  ∣  ( ◡ 𝑎  “  ℕ )  ∈  Fin } ) ) | 
						
							| 8 |  | eqid | ⊢ ( 𝐼  mPwSer  𝑆 )  =  ( 𝐼  mPwSer  𝑆 ) | 
						
							| 9 |  | eqid | ⊢ ( Base ‘ 𝑆 )  =  ( Base ‘ 𝑆 ) | 
						
							| 10 |  | eqid | ⊢ ( Base ‘ ( 𝐼  mPwSer  𝑆 ) )  =  ( Base ‘ ( 𝐼  mPwSer  𝑆 ) ) | 
						
							| 11 | 8 9 4 10 6 | psrbas | ⊢ ( ( 𝜑  ∧  𝐼  ∈  V )  →  ( Base ‘ ( 𝐼  mPwSer  𝑆 ) )  =  ( ( Base ‘ 𝑆 )  ↑m  { 𝑎  ∈  ( ℕ0  ↑m  𝐼 )  ∣  ( ◡ 𝑎  “  ℕ )  ∈  Fin } ) ) | 
						
							| 12 | 1 | adantr | ⊢ ( ( 𝜑  ∧  𝐼  ∈  V )  →  ( Base ‘ 𝑅 )  =  ( Base ‘ 𝑆 ) ) | 
						
							| 13 | 12 | oveq1d | ⊢ ( ( 𝜑  ∧  𝐼  ∈  V )  →  ( ( Base ‘ 𝑅 )  ↑m  { 𝑎  ∈  ( ℕ0  ↑m  𝐼 )  ∣  ( ◡ 𝑎  “  ℕ )  ∈  Fin } )  =  ( ( Base ‘ 𝑆 )  ↑m  { 𝑎  ∈  ( ℕ0  ↑m  𝐼 )  ∣  ( ◡ 𝑎  “  ℕ )  ∈  Fin } ) ) | 
						
							| 14 | 11 13 | eqtr4d | ⊢ ( ( 𝜑  ∧  𝐼  ∈  V )  →  ( Base ‘ ( 𝐼  mPwSer  𝑆 ) )  =  ( ( Base ‘ 𝑅 )  ↑m  { 𝑎  ∈  ( ℕ0  ↑m  𝐼 )  ∣  ( ◡ 𝑎  “  ℕ )  ∈  Fin } ) ) | 
						
							| 15 | 7 14 | eqtr4d | ⊢ ( ( 𝜑  ∧  𝐼  ∈  V )  →  ( Base ‘ ( 𝐼  mPwSer  𝑅 ) )  =  ( Base ‘ ( 𝐼  mPwSer  𝑆 ) ) ) | 
						
							| 16 |  | reldmpsr | ⊢ Rel  dom   mPwSer | 
						
							| 17 | 16 | ovprc1 | ⊢ ( ¬  𝐼  ∈  V  →  ( 𝐼  mPwSer  𝑅 )  =  ∅ ) | 
						
							| 18 | 16 | ovprc1 | ⊢ ( ¬  𝐼  ∈  V  →  ( 𝐼  mPwSer  𝑆 )  =  ∅ ) | 
						
							| 19 | 17 18 | eqtr4d | ⊢ ( ¬  𝐼  ∈  V  →  ( 𝐼  mPwSer  𝑅 )  =  ( 𝐼  mPwSer  𝑆 ) ) | 
						
							| 20 | 19 | fveq2d | ⊢ ( ¬  𝐼  ∈  V  →  ( Base ‘ ( 𝐼  mPwSer  𝑅 ) )  =  ( Base ‘ ( 𝐼  mPwSer  𝑆 ) ) ) | 
						
							| 21 | 20 | adantl | ⊢ ( ( 𝜑  ∧  ¬  𝐼  ∈  V )  →  ( Base ‘ ( 𝐼  mPwSer  𝑅 ) )  =  ( Base ‘ ( 𝐼  mPwSer  𝑆 ) ) ) | 
						
							| 22 | 15 21 | pm2.61dan | ⊢ ( 𝜑  →  ( Base ‘ ( 𝐼  mPwSer  𝑅 ) )  =  ( Base ‘ ( 𝐼  mPwSer  𝑆 ) ) ) |