1:: | |- (. A e. B ->. A e. B ).
|
2:: | |- (. A e. B ,. [. A / x ]. ( ph -> ( ps
-> ch ) ) ->. [. A / x ]. ( ph -> ( ps -> ch ) ) ).
|
3:1,2: | |- (. A e. B ,. [. A / x ]. ( ph -> ( ps
-> ch ) ) ->. ( [. A / x ]. ph -> [. A / x ]. ( ps -> ch ) ) ).
|
4:1: | |- (. A e. B ->. ( [. A / x ]. ( ps -> ch )
<-> ( [. A / x ]. ps -> [. A / x ]. ch ) ) ).
|
5:3,4: | |- (. A e. B ,. [. A / x ]. ( ph -> ( ps
-> ch ) ) ->. ( [. A / x ]. ph -> ( [. A / x ]. ps
-> [. A / x ]. ch ) ) ).
|
6:5: | |- (. A e. B ->. ( [. A / x ]. ( ph -> ( ps
-> ch ) ) -> ( [. A / x ]. ph -> ( [. A / x ]. ps
-> [. A / x ]. ch ) ) ) ).
|
7:: | |- (. A e. B ,. ( [. A / x ]. ph
-> ( [. A / x ]. ps -> [. A / x ]. ch ) ) ->. ( [. A / x ]. ph
-> ( [. A / x ]. ps -> [. A / x ]. ch ) ) ).
|
8:4,7: | |- (. A e. B ,. ( [. A / x ]. ph
-> ( [. A / x ]. ps -> [. A / x ]. ch ) ) ->. ( [. A / x ]. ph
-> [. A / x ]. ( ps -> ch ) ) ).
|
9:1: | |- (. A e. B ->. ( [. A / x ]. ( ph -> ( ps
-> ch ) ) <-> ( [. A / x ]. ph -> [. A / x ]. ( ps -> ch ) ) ) ).
|
10:8,9: | |- (. A e. B ,. ( [. A / x ]. ph
-> ( [. A / x ]. ps -> [. A / x ]. ch ) ) ->. [. A / x ]. ( ph -> ( ps
-> ch ) ) ).
|
11:10: | |- (. A e. B ->. ( ( [. A / x ]. ph
-> ( [. A / x ]. ps -> [. A / x ]. ch ) ) -> [. A / x ]. ( ph -> ( ps
-> ch ) ) ) ).
|
12:6,11: | |- (. A e. B ->. ( [. A / x ]. ( ph
-> ( ps -> ch ) ) <-> ( [. A / x ]. ph -> ( [. A / x ]. ps
-> [. A / x ]. ch ) ) ) ).
|
qed:12: | |- ( A e. B -> ( [. A / x ]. ( ph -> ( ps
-> ch ) ) <-> ( [. A / x ]. ph -> ( [. A / x ]. ps
-> [. A / x ]. ch ) ) ) )
|