Description: Virtual deduction proof of rspsbc2 . The following user's proof is completed by invoking mmj2's unify command and using mmj2's StepSelector to pick all remaining steps of the Metamath proof.
| 1:: | |- (. A e. B ->. A e. B ). | 
| 2:: | |- (. A e. B ,. C e. D ->. C e. D ). | 
| 3:: | |- (. A e. B ,. C e. D ,. A. x e. B A. y e. D ph ->. A. x e. B A. y e. D ph ). | 
| 4:1,3,?: e13 | |- (. A e. B ,. C e. D ,. A. x e. B A. y e. D ph ->. [. A / x ]. A. y e. D ph ). | 
| 5:1,4,?: e13 | |- (. A e. B ,. C e. D ,. A. x e. B A. y e. D ph ->. A. y e. D [. A / x ]. ph ). | 
| 6:2,5,?: e23 | |- (. A e. B ,. C e. D ,. A. x e. B A. y e. D ph ->. [. C / y ]. [. A / x ]. ph ). | 
| 7:6: | |- (. A e. B ,. C e. D ->. ( A. x e. B A. y e. D ph -> [. C / y ]. [. A / x ]. ph ) ). | 
| 8:7: | |- (. A e. B ->. ( C e. D -> ( A. x e. B A. y e. D ph -> [. C / y ]. [. A / x ]. ph ) ) ). | 
| qed:8: | |- ( A e. B -> ( C e. D -> ( A. x e. B A. y e. D ph -> [. C / y ]. [. A / x ]. ph ) ) ) | 
| Ref | Expression | ||
|---|---|---|---|
| Assertion | rspsbc2VD | ⊢ ( 𝐴 ∈ 𝐵 → ( 𝐶 ∈ 𝐷 → ( ∀ 𝑥 ∈ 𝐵 ∀ 𝑦 ∈ 𝐷 𝜑 → [ 𝐶 / 𝑦 ] [ 𝐴 / 𝑥 ] 𝜑 ) ) ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | idn2 | ⊢ ( 𝐴 ∈ 𝐵 , 𝐶 ∈ 𝐷 ▶ 𝐶 ∈ 𝐷 ) | |
| 2 | idn1 | ⊢ ( 𝐴 ∈ 𝐵 ▶ 𝐴 ∈ 𝐵 ) | |
| 3 | idn3 | ⊢ ( 𝐴 ∈ 𝐵 , 𝐶 ∈ 𝐷 , ∀ 𝑥 ∈ 𝐵 ∀ 𝑦 ∈ 𝐷 𝜑 ▶ ∀ 𝑥 ∈ 𝐵 ∀ 𝑦 ∈ 𝐷 𝜑 ) | |
| 4 | rspsbc | ⊢ ( 𝐴 ∈ 𝐵 → ( ∀ 𝑥 ∈ 𝐵 ∀ 𝑦 ∈ 𝐷 𝜑 → [ 𝐴 / 𝑥 ] ∀ 𝑦 ∈ 𝐷 𝜑 ) ) | |
| 5 | 2 3 4 | e13 | ⊢ ( 𝐴 ∈ 𝐵 , 𝐶 ∈ 𝐷 , ∀ 𝑥 ∈ 𝐵 ∀ 𝑦 ∈ 𝐷 𝜑 ▶ [ 𝐴 / 𝑥 ] ∀ 𝑦 ∈ 𝐷 𝜑 ) | 
| 6 | sbcralg | ⊢ ( 𝐴 ∈ 𝐵 → ( [ 𝐴 / 𝑥 ] ∀ 𝑦 ∈ 𝐷 𝜑 ↔ ∀ 𝑦 ∈ 𝐷 [ 𝐴 / 𝑥 ] 𝜑 ) ) | |
| 7 | 6 | biimpd | ⊢ ( 𝐴 ∈ 𝐵 → ( [ 𝐴 / 𝑥 ] ∀ 𝑦 ∈ 𝐷 𝜑 → ∀ 𝑦 ∈ 𝐷 [ 𝐴 / 𝑥 ] 𝜑 ) ) | 
| 8 | 2 5 7 | e13 | ⊢ ( 𝐴 ∈ 𝐵 , 𝐶 ∈ 𝐷 , ∀ 𝑥 ∈ 𝐵 ∀ 𝑦 ∈ 𝐷 𝜑 ▶ ∀ 𝑦 ∈ 𝐷 [ 𝐴 / 𝑥 ] 𝜑 ) | 
| 9 | rspsbc | ⊢ ( 𝐶 ∈ 𝐷 → ( ∀ 𝑦 ∈ 𝐷 [ 𝐴 / 𝑥 ] 𝜑 → [ 𝐶 / 𝑦 ] [ 𝐴 / 𝑥 ] 𝜑 ) ) | |
| 10 | 1 8 9 | e23 | ⊢ ( 𝐴 ∈ 𝐵 , 𝐶 ∈ 𝐷 , ∀ 𝑥 ∈ 𝐵 ∀ 𝑦 ∈ 𝐷 𝜑 ▶ [ 𝐶 / 𝑦 ] [ 𝐴 / 𝑥 ] 𝜑 ) | 
| 11 | 10 | in3 | ⊢ ( 𝐴 ∈ 𝐵 , 𝐶 ∈ 𝐷 ▶ ( ∀ 𝑥 ∈ 𝐵 ∀ 𝑦 ∈ 𝐷 𝜑 → [ 𝐶 / 𝑦 ] [ 𝐴 / 𝑥 ] 𝜑 ) ) | 
| 12 | 11 | in2 | ⊢ ( 𝐴 ∈ 𝐵 ▶ ( 𝐶 ∈ 𝐷 → ( ∀ 𝑥 ∈ 𝐵 ∀ 𝑦 ∈ 𝐷 𝜑 → [ 𝐶 / 𝑦 ] [ 𝐴 / 𝑥 ] 𝜑 ) ) ) | 
| 13 | 12 | in1 | ⊢ ( 𝐴 ∈ 𝐵 → ( 𝐶 ∈ 𝐷 → ( ∀ 𝑥 ∈ 𝐵 ∀ 𝑦 ∈ 𝐷 𝜑 → [ 𝐶 / 𝑦 ] [ 𝐴 / 𝑥 ] 𝜑 ) ) ) |