| Step | Hyp | Ref | Expression | 
						
							| 1 |  | pthsonfval.v | ⊢ 𝑉  =  ( Vtx ‘ 𝐺 ) | 
						
							| 2 | 1 | isspthson | ⊢ ( ( ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑉 )  ∧  ( 𝐹  ∈  V  ∧  𝑃  ∈  V ) )  →  ( 𝐹 ( 𝐴 ( SPathsOn ‘ 𝐺 ) 𝐵 ) 𝑃  ↔  ( 𝐹 ( 𝐴 ( TrailsOn ‘ 𝐺 ) 𝐵 ) 𝑃  ∧  𝐹 ( SPaths ‘ 𝐺 ) 𝑃 ) ) ) | 
						
							| 3 | 2 | 3adantl1 | ⊢ ( ( ( 𝐺  ∈  V  ∧  𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑉 )  ∧  ( 𝐹  ∈  V  ∧  𝑃  ∈  V ) )  →  ( 𝐹 ( 𝐴 ( SPathsOn ‘ 𝐺 ) 𝐵 ) 𝑃  ↔  ( 𝐹 ( 𝐴 ( TrailsOn ‘ 𝐺 ) 𝐵 ) 𝑃  ∧  𝐹 ( SPaths ‘ 𝐺 ) 𝑃 ) ) ) | 
						
							| 4 |  | df-spthson | ⊢ SPathsOn  =  ( 𝑔  ∈  V  ↦  ( 𝑎  ∈  ( Vtx ‘ 𝑔 ) ,  𝑏  ∈  ( Vtx ‘ 𝑔 )  ↦  { 〈 𝑓 ,  𝑝 〉  ∣  ( 𝑓 ( 𝑎 ( TrailsOn ‘ 𝑔 ) 𝑏 ) 𝑝  ∧  𝑓 ( SPaths ‘ 𝑔 ) 𝑝 ) } ) ) | 
						
							| 5 | 1 3 4 | wksonproplem | ⊢ ( 𝐹 ( 𝐴 ( SPathsOn ‘ 𝐺 ) 𝐵 ) 𝑃  →  ( ( 𝐺  ∈  V  ∧  𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑉 )  ∧  ( 𝐹  ∈  V  ∧  𝑃  ∈  V )  ∧  ( 𝐹 ( 𝐴 ( TrailsOn ‘ 𝐺 ) 𝐵 ) 𝑃  ∧  𝐹 ( SPaths ‘ 𝐺 ) 𝑃 ) ) ) |