let f be Function; for a, d being object holds NDentry (<*f*>,<*a*>,d) = {[a,(f . d)]}
let a, d be object ; NDentry (<*f*>,<*a*>,d) = {[a,(f . d)]}
set X = <*a*>;
set G = <*f*>;
set A = {[a,(f . d)]};
set N = NDdataSeq (<*f*>,<*a*>,d);
set F = NDentry (<*f*>,<*a*>,d);
A1:
dom (NDdataSeq (<*f*>,<*a*>,d)) = dom <*a*>
by Def4;
A2:
dom <*a*> = {1}
by FINSEQ_1:2, FINSEQ_1:38;
A3:
1 in {1}
by TARSKI:def 1;
then A4:
(NDdataSeq (<*f*>,<*a*>,d)) . 1 = [(<*a*> . 1),((<*f*> . 1) . d)]
by A2, Def4;
thus
NDentry (<*f*>,<*a*>,d) c= {[a,(f . d)]}
XBOOLE_0:def 10 {[a,(f . d)]} c= NDentry (<*f*>,<*a*>,d)proof
let y be
object ;
TARSKI:def 3 ( not y in NDentry (<*f*>,<*a*>,d) or y in {[a,(f . d)]} )
assume
y in NDentry (
<*f*>,
<*a*>,
d)
;
y in {[a,(f . d)]}
then consider z being
object such that A6:
z in dom (NDdataSeq (<*f*>,<*a*>,d))
and A7:
(NDdataSeq (<*f*>,<*a*>,d)) . z = y
by FUNCT_1:def 3;
z = 1
by A1, A2, A6, TARSKI:def 1;
hence
y in {[a,(f . d)]}
by A4, A7, TARSKI:def 1;
verum
end;
let y, z be object ; RELAT_1:def 3 ( not [y,z] in {[a,(f . d)]} or [y,z] in NDentry (<*f*>,<*a*>,d) )
assume
[y,z] in {[a,(f . d)]}
; [y,z] in NDentry (<*f*>,<*a*>,d)
then
[y,z] = [a,(f . d)]
by TARSKI:def 1;
hence
[y,z] in NDentry (<*f*>,<*a*>,d)
by A1, A2, A3, A4, FUNCT_1:def 3; verum