| Step | Hyp | Ref | Expression | 
						
							| 1 |  | cvmliftiota.b | ⊢ 𝐵  =  ∪  𝐶 | 
						
							| 2 |  | cvmliftiota.h | ⊢ 𝐻  =  ( ℩ 𝑓  ∈  ( II  Cn  𝐶 ) ( ( 𝐹  ∘  𝑓 )  =  𝐺  ∧  ( 𝑓 ‘ 0 )  =  𝑃 ) ) | 
						
							| 3 |  | cvmliftiota.f | ⊢ ( 𝜑  →  𝐹  ∈  ( 𝐶  CovMap  𝐽 ) ) | 
						
							| 4 |  | cvmliftiota.g | ⊢ ( 𝜑  →  𝐺  ∈  ( II  Cn  𝐽 ) ) | 
						
							| 5 |  | cvmliftiota.p | ⊢ ( 𝜑  →  𝑃  ∈  𝐵 ) | 
						
							| 6 |  | cvmliftiota.e | ⊢ ( 𝜑  →  ( 𝐹 ‘ 𝑃 )  =  ( 𝐺 ‘ 0 ) ) | 
						
							| 7 |  | coeq2 | ⊢ ( 𝑓  =  𝑔  →  ( 𝐹  ∘  𝑓 )  =  ( 𝐹  ∘  𝑔 ) ) | 
						
							| 8 | 7 | eqeq1d | ⊢ ( 𝑓  =  𝑔  →  ( ( 𝐹  ∘  𝑓 )  =  𝐺  ↔  ( 𝐹  ∘  𝑔 )  =  𝐺 ) ) | 
						
							| 9 |  | fveq1 | ⊢ ( 𝑓  =  𝑔  →  ( 𝑓 ‘ 0 )  =  ( 𝑔 ‘ 0 ) ) | 
						
							| 10 | 9 | eqeq1d | ⊢ ( 𝑓  =  𝑔  →  ( ( 𝑓 ‘ 0 )  =  𝑃  ↔  ( 𝑔 ‘ 0 )  =  𝑃 ) ) | 
						
							| 11 | 8 10 | anbi12d | ⊢ ( 𝑓  =  𝑔  →  ( ( ( 𝐹  ∘  𝑓 )  =  𝐺  ∧  ( 𝑓 ‘ 0 )  =  𝑃 )  ↔  ( ( 𝐹  ∘  𝑔 )  =  𝐺  ∧  ( 𝑔 ‘ 0 )  =  𝑃 ) ) ) | 
						
							| 12 | 11 | cbvriotavw | ⊢ ( ℩ 𝑓  ∈  ( II  Cn  𝐶 ) ( ( 𝐹  ∘  𝑓 )  =  𝐺  ∧  ( 𝑓 ‘ 0 )  =  𝑃 ) )  =  ( ℩ 𝑔  ∈  ( II  Cn  𝐶 ) ( ( 𝐹  ∘  𝑔 )  =  𝐺  ∧  ( 𝑔 ‘ 0 )  =  𝑃 ) ) | 
						
							| 13 | 2 12 | eqtri | ⊢ 𝐻  =  ( ℩ 𝑔  ∈  ( II  Cn  𝐶 ) ( ( 𝐹  ∘  𝑔 )  =  𝐺  ∧  ( 𝑔 ‘ 0 )  =  𝑃 ) ) | 
						
							| 14 | 1 | cvmlift | ⊢ ( ( ( 𝐹  ∈  ( 𝐶  CovMap  𝐽 )  ∧  𝐺  ∈  ( II  Cn  𝐽 ) )  ∧  ( 𝑃  ∈  𝐵  ∧  ( 𝐹 ‘ 𝑃 )  =  ( 𝐺 ‘ 0 ) ) )  →  ∃! 𝑔  ∈  ( II  Cn  𝐶 ) ( ( 𝐹  ∘  𝑔 )  =  𝐺  ∧  ( 𝑔 ‘ 0 )  =  𝑃 ) ) | 
						
							| 15 | 3 4 5 6 14 | syl22anc | ⊢ ( 𝜑  →  ∃! 𝑔  ∈  ( II  Cn  𝐶 ) ( ( 𝐹  ∘  𝑔 )  =  𝐺  ∧  ( 𝑔 ‘ 0 )  =  𝑃 ) ) | 
						
							| 16 |  | riotacl2 | ⊢ ( ∃! 𝑔  ∈  ( II  Cn  𝐶 ) ( ( 𝐹  ∘  𝑔 )  =  𝐺  ∧  ( 𝑔 ‘ 0 )  =  𝑃 )  →  ( ℩ 𝑔  ∈  ( II  Cn  𝐶 ) ( ( 𝐹  ∘  𝑔 )  =  𝐺  ∧  ( 𝑔 ‘ 0 )  =  𝑃 ) )  ∈  { 𝑔  ∈  ( II  Cn  𝐶 )  ∣  ( ( 𝐹  ∘  𝑔 )  =  𝐺  ∧  ( 𝑔 ‘ 0 )  =  𝑃 ) } ) | 
						
							| 17 | 15 16 | syl | ⊢ ( 𝜑  →  ( ℩ 𝑔  ∈  ( II  Cn  𝐶 ) ( ( 𝐹  ∘  𝑔 )  =  𝐺  ∧  ( 𝑔 ‘ 0 )  =  𝑃 ) )  ∈  { 𝑔  ∈  ( II  Cn  𝐶 )  ∣  ( ( 𝐹  ∘  𝑔 )  =  𝐺  ∧  ( 𝑔 ‘ 0 )  =  𝑃 ) } ) | 
						
							| 18 | 13 17 | eqeltrid | ⊢ ( 𝜑  →  𝐻  ∈  { 𝑔  ∈  ( II  Cn  𝐶 )  ∣  ( ( 𝐹  ∘  𝑔 )  =  𝐺  ∧  ( 𝑔 ‘ 0 )  =  𝑃 ) } ) | 
						
							| 19 |  | coeq2 | ⊢ ( 𝑔  =  𝐻  →  ( 𝐹  ∘  𝑔 )  =  ( 𝐹  ∘  𝐻 ) ) | 
						
							| 20 | 19 | eqeq1d | ⊢ ( 𝑔  =  𝐻  →  ( ( 𝐹  ∘  𝑔 )  =  𝐺  ↔  ( 𝐹  ∘  𝐻 )  =  𝐺 ) ) | 
						
							| 21 |  | fveq1 | ⊢ ( 𝑔  =  𝐻  →  ( 𝑔 ‘ 0 )  =  ( 𝐻 ‘ 0 ) ) | 
						
							| 22 | 21 | eqeq1d | ⊢ ( 𝑔  =  𝐻  →  ( ( 𝑔 ‘ 0 )  =  𝑃  ↔  ( 𝐻 ‘ 0 )  =  𝑃 ) ) | 
						
							| 23 | 20 22 | anbi12d | ⊢ ( 𝑔  =  𝐻  →  ( ( ( 𝐹  ∘  𝑔 )  =  𝐺  ∧  ( 𝑔 ‘ 0 )  =  𝑃 )  ↔  ( ( 𝐹  ∘  𝐻 )  =  𝐺  ∧  ( 𝐻 ‘ 0 )  =  𝑃 ) ) ) | 
						
							| 24 | 23 | elrab | ⊢ ( 𝐻  ∈  { 𝑔  ∈  ( II  Cn  𝐶 )  ∣  ( ( 𝐹  ∘  𝑔 )  =  𝐺  ∧  ( 𝑔 ‘ 0 )  =  𝑃 ) }  ↔  ( 𝐻  ∈  ( II  Cn  𝐶 )  ∧  ( ( 𝐹  ∘  𝐻 )  =  𝐺  ∧  ( 𝐻 ‘ 0 )  =  𝑃 ) ) ) | 
						
							| 25 |  | 3anass | ⊢ ( ( 𝐻  ∈  ( II  Cn  𝐶 )  ∧  ( 𝐹  ∘  𝐻 )  =  𝐺  ∧  ( 𝐻 ‘ 0 )  =  𝑃 )  ↔  ( 𝐻  ∈  ( II  Cn  𝐶 )  ∧  ( ( 𝐹  ∘  𝐻 )  =  𝐺  ∧  ( 𝐻 ‘ 0 )  =  𝑃 ) ) ) | 
						
							| 26 | 24 25 | bitr4i | ⊢ ( 𝐻  ∈  { 𝑔  ∈  ( II  Cn  𝐶 )  ∣  ( ( 𝐹  ∘  𝑔 )  =  𝐺  ∧  ( 𝑔 ‘ 0 )  =  𝑃 ) }  ↔  ( 𝐻  ∈  ( II  Cn  𝐶 )  ∧  ( 𝐹  ∘  𝐻 )  =  𝐺  ∧  ( 𝐻 ‘ 0 )  =  𝑃 ) ) | 
						
							| 27 | 18 26 | sylib | ⊢ ( 𝜑  →  ( 𝐻  ∈  ( II  Cn  𝐶 )  ∧  ( 𝐹  ∘  𝐻 )  =  𝐺  ∧  ( 𝐻 ‘ 0 )  =  𝑃 ) ) |