theorem eqsubsnabd (G: wff) (a: nat) {x: nat} (p: wff x): $ G -> p -> x = a $ > $ G -> subsn {x | p} $;
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | subsnss | {x | p} C_ {x | x = a} -> subsn {x | x = a} -> subsn {x | p} |
|
2 | hyp h | G -> p -> x = a |
|
3 | 2 | ssabd | G -> {x | p} C_ {x | x = a} |
4 | subsnsn2 | subsn {x | x = a} |
|
5 | 4 | a1i | G -> subsn {x | x = a} |
6 | 1, 3, 5 | sylc | G -> subsn {x | p} |