defpred S1[ set , Element of R] means ex N being strict net of R st
( N = $1 & $2 is_S-limit_of N );
consider C being Relation of (NetUniv R), the carrier of R such that
A1:
for x being Element of NetUniv R
for y being Element of R holds
( [x,y] in C iff S1[x,y] )
from RELSET_1:sch 2();
reconsider C = C as Convergence-Class of R by YELLOW_6:def 18;
take
C
; for N being strict net of R st N in NetUniv R holds
for p being Element of R holds
( [N,p] in C iff p is_S-limit_of N )
let N be strict net of R; ( N in NetUniv R implies for p being Element of R holds
( [N,p] in C iff p is_S-limit_of N ) )
assume A2:
N in NetUniv R
; for p being Element of R holds
( [N,p] in C iff p is_S-limit_of N )
let p be Element of R; ( [N,p] in C iff p is_S-limit_of N )
thus
( p is_S-limit_of N implies [N,p] in C )
by A1, A2; verum