let n be Element of NAT ; 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); 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); ex q being Point of (TOP-REAL n) st
( q in A & dist p,A = dist p,q )
consider q, p9 being Point of (TOP-REAL n) such that
A1:
q in A
and
A2:
( p9 in {p} & dist_min A,{p} = dist q,p9 )
by Th42;
take
q
; ( q in A & dist p,A = dist p,q )
thus
q in A
by A1; dist p,A = dist p,q
thus
dist p,A = dist p,q
by A2, TARSKI:def 1; verum