| Step | Hyp | Ref | Expression | 
						
							| 1 |  | ffn | ⊢ ( 𝐸 : dom  𝐸 ⟶ 𝑅  →  𝐸  Fn  dom  𝐸 ) | 
						
							| 2 | 1 | adantl | ⊢ ( ( 𝐹 : { 𝑋 ,  𝑌 } ⟶ dom  𝐸  ∧  𝐸 : dom  𝐸 ⟶ 𝑅 )  →  𝐸  Fn  dom  𝐸 ) | 
						
							| 3 | 2 | adantr | ⊢ ( ( ( 𝐹 : { 𝑋 ,  𝑌 } ⟶ dom  𝐸  ∧  𝐸 : dom  𝐸 ⟶ 𝑅 )  ∧  ( 𝑋  ∈  𝑉  ∧  𝑌  ∈  𝑊 ) )  →  𝐸  Fn  dom  𝐸 ) | 
						
							| 4 |  | simpll | ⊢ ( ( ( 𝐹 : { 𝑋 ,  𝑌 } ⟶ dom  𝐸  ∧  𝐸 : dom  𝐸 ⟶ 𝑅 )  ∧  ( 𝑋  ∈  𝑉  ∧  𝑌  ∈  𝑊 ) )  →  𝐹 : { 𝑋 ,  𝑌 } ⟶ dom  𝐸 ) | 
						
							| 5 |  | prid1g | ⊢ ( 𝑋  ∈  𝑉  →  𝑋  ∈  { 𝑋 ,  𝑌 } ) | 
						
							| 6 | 5 | adantr | ⊢ ( ( 𝑋  ∈  𝑉  ∧  𝑌  ∈  𝑊 )  →  𝑋  ∈  { 𝑋 ,  𝑌 } ) | 
						
							| 7 | 6 | adantl | ⊢ ( ( ( 𝐹 : { 𝑋 ,  𝑌 } ⟶ dom  𝐸  ∧  𝐸 : dom  𝐸 ⟶ 𝑅 )  ∧  ( 𝑋  ∈  𝑉  ∧  𝑌  ∈  𝑊 ) )  →  𝑋  ∈  { 𝑋 ,  𝑌 } ) | 
						
							| 8 | 4 7 | ffvelcdmd | ⊢ ( ( ( 𝐹 : { 𝑋 ,  𝑌 } ⟶ dom  𝐸  ∧  𝐸 : dom  𝐸 ⟶ 𝑅 )  ∧  ( 𝑋  ∈  𝑉  ∧  𝑌  ∈  𝑊 ) )  →  ( 𝐹 ‘ 𝑋 )  ∈  dom  𝐸 ) | 
						
							| 9 |  | prid2g | ⊢ ( 𝑌  ∈  𝑊  →  𝑌  ∈  { 𝑋 ,  𝑌 } ) | 
						
							| 10 | 9 | ad2antll | ⊢ ( ( ( 𝐹 : { 𝑋 ,  𝑌 } ⟶ dom  𝐸  ∧  𝐸 : dom  𝐸 ⟶ 𝑅 )  ∧  ( 𝑋  ∈  𝑉  ∧  𝑌  ∈  𝑊 ) )  →  𝑌  ∈  { 𝑋 ,  𝑌 } ) | 
						
							| 11 | 4 10 | ffvelcdmd | ⊢ ( ( ( 𝐹 : { 𝑋 ,  𝑌 } ⟶ dom  𝐸  ∧  𝐸 : dom  𝐸 ⟶ 𝑅 )  ∧  ( 𝑋  ∈  𝑉  ∧  𝑌  ∈  𝑊 ) )  →  ( 𝐹 ‘ 𝑌 )  ∈  dom  𝐸 ) | 
						
							| 12 |  | fnimapr | ⊢ ( ( 𝐸  Fn  dom  𝐸  ∧  ( 𝐹 ‘ 𝑋 )  ∈  dom  𝐸  ∧  ( 𝐹 ‘ 𝑌 )  ∈  dom  𝐸 )  →  ( 𝐸  “  { ( 𝐹 ‘ 𝑋 ) ,  ( 𝐹 ‘ 𝑌 ) } )  =  { ( 𝐸 ‘ ( 𝐹 ‘ 𝑋 ) ) ,  ( 𝐸 ‘ ( 𝐹 ‘ 𝑌 ) ) } ) | 
						
							| 13 | 3 8 11 12 | syl3anc | ⊢ ( ( ( 𝐹 : { 𝑋 ,  𝑌 } ⟶ dom  𝐸  ∧  𝐸 : dom  𝐸 ⟶ 𝑅 )  ∧  ( 𝑋  ∈  𝑉  ∧  𝑌  ∈  𝑊 ) )  →  ( 𝐸  “  { ( 𝐹 ‘ 𝑋 ) ,  ( 𝐹 ‘ 𝑌 ) } )  =  { ( 𝐸 ‘ ( 𝐹 ‘ 𝑋 ) ) ,  ( 𝐸 ‘ ( 𝐹 ‘ 𝑌 ) ) } ) | 
						
							| 14 | 13 | ex | ⊢ ( ( 𝐹 : { 𝑋 ,  𝑌 } ⟶ dom  𝐸  ∧  𝐸 : dom  𝐸 ⟶ 𝑅 )  →  ( ( 𝑋  ∈  𝑉  ∧  𝑌  ∈  𝑊 )  →  ( 𝐸  “  { ( 𝐹 ‘ 𝑋 ) ,  ( 𝐹 ‘ 𝑌 ) } )  =  { ( 𝐸 ‘ ( 𝐹 ‘ 𝑋 ) ) ,  ( 𝐸 ‘ ( 𝐹 ‘ 𝑌 ) ) } ) ) | 
						
							| 15 | 14 | adantr | ⊢ ( ( ( 𝐹 : { 𝑋 ,  𝑌 } ⟶ dom  𝐸  ∧  𝐸 : dom  𝐸 ⟶ 𝑅 )  ∧  ( ( 𝐸 ‘ ( 𝐹 ‘ 𝑋 ) )  =  𝐴  ∧  ( 𝐸 ‘ ( 𝐹 ‘ 𝑌 ) )  =  𝐵 ) )  →  ( ( 𝑋  ∈  𝑉  ∧  𝑌  ∈  𝑊 )  →  ( 𝐸  “  { ( 𝐹 ‘ 𝑋 ) ,  ( 𝐹 ‘ 𝑌 ) } )  =  { ( 𝐸 ‘ ( 𝐹 ‘ 𝑋 ) ) ,  ( 𝐸 ‘ ( 𝐹 ‘ 𝑌 ) ) } ) ) | 
						
							| 16 | 15 | impcom | ⊢ ( ( ( 𝑋  ∈  𝑉  ∧  𝑌  ∈  𝑊 )  ∧  ( ( 𝐹 : { 𝑋 ,  𝑌 } ⟶ dom  𝐸  ∧  𝐸 : dom  𝐸 ⟶ 𝑅 )  ∧  ( ( 𝐸 ‘ ( 𝐹 ‘ 𝑋 ) )  =  𝐴  ∧  ( 𝐸 ‘ ( 𝐹 ‘ 𝑌 ) )  =  𝐵 ) ) )  →  ( 𝐸  “  { ( 𝐹 ‘ 𝑋 ) ,  ( 𝐹 ‘ 𝑌 ) } )  =  { ( 𝐸 ‘ ( 𝐹 ‘ 𝑋 ) ) ,  ( 𝐸 ‘ ( 𝐹 ‘ 𝑌 ) ) } ) | 
						
							| 17 |  | ffn | ⊢ ( 𝐹 : { 𝑋 ,  𝑌 } ⟶ dom  𝐸  →  𝐹  Fn  { 𝑋 ,  𝑌 } ) | 
						
							| 18 |  | rnfdmpr | ⊢ ( ( 𝑋  ∈  𝑉  ∧  𝑌  ∈  𝑊 )  →  ( 𝐹  Fn  { 𝑋 ,  𝑌 }  →  ran  𝐹  =  { ( 𝐹 ‘ 𝑋 ) ,  ( 𝐹 ‘ 𝑌 ) } ) ) | 
						
							| 19 | 17 18 | syl5com | ⊢ ( 𝐹 : { 𝑋 ,  𝑌 } ⟶ dom  𝐸  →  ( ( 𝑋  ∈  𝑉  ∧  𝑌  ∈  𝑊 )  →  ran  𝐹  =  { ( 𝐹 ‘ 𝑋 ) ,  ( 𝐹 ‘ 𝑌 ) } ) ) | 
						
							| 20 | 19 | adantr | ⊢ ( ( 𝐹 : { 𝑋 ,  𝑌 } ⟶ dom  𝐸  ∧  𝐸 : dom  𝐸 ⟶ 𝑅 )  →  ( ( 𝑋  ∈  𝑉  ∧  𝑌  ∈  𝑊 )  →  ran  𝐹  =  { ( 𝐹 ‘ 𝑋 ) ,  ( 𝐹 ‘ 𝑌 ) } ) ) | 
						
							| 21 | 20 | adantr | ⊢ ( ( ( 𝐹 : { 𝑋 ,  𝑌 } ⟶ dom  𝐸  ∧  𝐸 : dom  𝐸 ⟶ 𝑅 )  ∧  ( ( 𝐸 ‘ ( 𝐹 ‘ 𝑋 ) )  =  𝐴  ∧  ( 𝐸 ‘ ( 𝐹 ‘ 𝑌 ) )  =  𝐵 ) )  →  ( ( 𝑋  ∈  𝑉  ∧  𝑌  ∈  𝑊 )  →  ran  𝐹  =  { ( 𝐹 ‘ 𝑋 ) ,  ( 𝐹 ‘ 𝑌 ) } ) ) | 
						
							| 22 | 21 | impcom | ⊢ ( ( ( 𝑋  ∈  𝑉  ∧  𝑌  ∈  𝑊 )  ∧  ( ( 𝐹 : { 𝑋 ,  𝑌 } ⟶ dom  𝐸  ∧  𝐸 : dom  𝐸 ⟶ 𝑅 )  ∧  ( ( 𝐸 ‘ ( 𝐹 ‘ 𝑋 ) )  =  𝐴  ∧  ( 𝐸 ‘ ( 𝐹 ‘ 𝑌 ) )  =  𝐵 ) ) )  →  ran  𝐹  =  { ( 𝐹 ‘ 𝑋 ) ,  ( 𝐹 ‘ 𝑌 ) } ) | 
						
							| 23 | 22 | eqcomd | ⊢ ( ( ( 𝑋  ∈  𝑉  ∧  𝑌  ∈  𝑊 )  ∧  ( ( 𝐹 : { 𝑋 ,  𝑌 } ⟶ dom  𝐸  ∧  𝐸 : dom  𝐸 ⟶ 𝑅 )  ∧  ( ( 𝐸 ‘ ( 𝐹 ‘ 𝑋 ) )  =  𝐴  ∧  ( 𝐸 ‘ ( 𝐹 ‘ 𝑌 ) )  =  𝐵 ) ) )  →  { ( 𝐹 ‘ 𝑋 ) ,  ( 𝐹 ‘ 𝑌 ) }  =  ran  𝐹 ) | 
						
							| 24 | 23 | imaeq2d | ⊢ ( ( ( 𝑋  ∈  𝑉  ∧  𝑌  ∈  𝑊 )  ∧  ( ( 𝐹 : { 𝑋 ,  𝑌 } ⟶ dom  𝐸  ∧  𝐸 : dom  𝐸 ⟶ 𝑅 )  ∧  ( ( 𝐸 ‘ ( 𝐹 ‘ 𝑋 ) )  =  𝐴  ∧  ( 𝐸 ‘ ( 𝐹 ‘ 𝑌 ) )  =  𝐵 ) ) )  →  ( 𝐸  “  { ( 𝐹 ‘ 𝑋 ) ,  ( 𝐹 ‘ 𝑌 ) } )  =  ( 𝐸  “  ran  𝐹 ) ) | 
						
							| 25 |  | preq12 | ⊢ ( ( ( 𝐸 ‘ ( 𝐹 ‘ 𝑋 ) )  =  𝐴  ∧  ( 𝐸 ‘ ( 𝐹 ‘ 𝑌 ) )  =  𝐵 )  →  { ( 𝐸 ‘ ( 𝐹 ‘ 𝑋 ) ) ,  ( 𝐸 ‘ ( 𝐹 ‘ 𝑌 ) ) }  =  { 𝐴 ,  𝐵 } ) | 
						
							| 26 | 25 | ad2antll | ⊢ ( ( ( 𝑋  ∈  𝑉  ∧  𝑌  ∈  𝑊 )  ∧  ( ( 𝐹 : { 𝑋 ,  𝑌 } ⟶ dom  𝐸  ∧  𝐸 : dom  𝐸 ⟶ 𝑅 )  ∧  ( ( 𝐸 ‘ ( 𝐹 ‘ 𝑋 ) )  =  𝐴  ∧  ( 𝐸 ‘ ( 𝐹 ‘ 𝑌 ) )  =  𝐵 ) ) )  →  { ( 𝐸 ‘ ( 𝐹 ‘ 𝑋 ) ) ,  ( 𝐸 ‘ ( 𝐹 ‘ 𝑌 ) ) }  =  { 𝐴 ,  𝐵 } ) | 
						
							| 27 | 16 24 26 | 3eqtr3d | ⊢ ( ( ( 𝑋  ∈  𝑉  ∧  𝑌  ∈  𝑊 )  ∧  ( ( 𝐹 : { 𝑋 ,  𝑌 } ⟶ dom  𝐸  ∧  𝐸 : dom  𝐸 ⟶ 𝑅 )  ∧  ( ( 𝐸 ‘ ( 𝐹 ‘ 𝑋 ) )  =  𝐴  ∧  ( 𝐸 ‘ ( 𝐹 ‘ 𝑌 ) )  =  𝐵 ) ) )  →  ( 𝐸  “  ran  𝐹 )  =  { 𝐴 ,  𝐵 } ) | 
						
							| 28 | 27 | ex | ⊢ ( ( 𝑋  ∈  𝑉  ∧  𝑌  ∈  𝑊 )  →  ( ( ( 𝐹 : { 𝑋 ,  𝑌 } ⟶ dom  𝐸  ∧  𝐸 : dom  𝐸 ⟶ 𝑅 )  ∧  ( ( 𝐸 ‘ ( 𝐹 ‘ 𝑋 ) )  =  𝐴  ∧  ( 𝐸 ‘ ( 𝐹 ‘ 𝑌 ) )  =  𝐵 ) )  →  ( 𝐸  “  ran  𝐹 )  =  { 𝐴 ,  𝐵 } ) ) |