let S be Language; for SQ being S -sequents-like set
for Sq being S -sequent-like object
for R being Relation of (bool (S -sequents)),(S -sequents) st [SQ,Sq] in R holds
Sq is 1,SQ,{(FuncRule R)} -derivable
let SQ be S -sequents-like set ; for Sq being S -sequent-like object
for R being Relation of (bool (S -sequents)),(S -sequents) st [SQ,Sq] in R holds
Sq is 1,SQ,{(FuncRule R)} -derivable
let Sq be S -sequent-like object ; for R being Relation of (bool (S -sequents)),(S -sequents) st [SQ,Sq] in R holds
Sq is 1,SQ,{(FuncRule R)} -derivable
set Q = S -sequents ;
let R be Relation of (bool (S -sequents)),(S -sequents); ( [SQ,Sq] in R implies Sq is 1,SQ,{(FuncRule R)} -derivable )
set F = FuncRule R;
set O = OneStep {(FuncRule R)};
reconsider Seqts = SQ as Subset of (S -sequents) by Def3;
reconsider seqt = Sq as Element of S -sequents by Def2;
A1: FuncRule R =
OneStep {(FuncRule R)}
by Lm6
.=
(1,{(FuncRule R)}) -derivables
by FUNCT_7:70
;
assume
[SQ,Sq] in R
; Sq is 1,SQ,{(FuncRule R)} -derivable
then
seqt in ((1,{(FuncRule R)}) -derivables) . Seqts
by A1, Lm27;
hence
Sq is 1,SQ,{(FuncRule R)} -derivable
; verum