let n be Element of NAT ; :: thesis: for A being non empty compact Subset of (TOP-REAL n)
for p being Point of (TOP-REAL n) ex q being Point of (TOP-REAL n) st
( q in A & dist p,A = dist p,q )
let A be non empty compact Subset of (TOP-REAL n); :: thesis: for p being Point of (TOP-REAL n) ex q being Point of (TOP-REAL n) st
( q in A & dist p,A = dist p,q )
let p be Point of (TOP-REAL n); :: thesis: ex q being Point of (TOP-REAL n) st
( q in A & dist p,A = dist p,q )
consider q, p' being Point of (TOP-REAL n) such that
A1:
q in A
and
A2:
p' in {p}
and
A3:
dist_min A,{p} = dist q,p'
by Th42;
take
q
; :: thesis: ( q in A & dist p,A = dist p,q )
thus
q in A
by A1; :: thesis: dist p,A = dist p,q
thus
dist p,A = dist p,q
by A2, A3, TARSKI:def 1; :: thesis: verum