let r be Real; for n being non zero Nat
for p being Element of (EMINFTY n)
for e being Point of (Euclid n) st e = p holds
Ball (p,r) = OpenHypercube (e,r)
let n be non zero Nat; for p being Element of (EMINFTY n)
for e being Point of (Euclid n) st e = p holds
Ball (p,r) = OpenHypercube (e,r)
let p be Element of (EMINFTY n); for e being Point of (Euclid n) st e = p holds
Ball (p,r) = OpenHypercube (e,r)
let e be Point of (Euclid n); ( e = p implies Ball (p,r) = OpenHypercube (e,r) )
assume A1:
e = p
; Ball (p,r) = OpenHypercube (e,r)
Ball (p,r) = product (Intervals ((@ p),r))
by Th68;
hence
Ball (p,r) = OpenHypercube (e,r)
by A1; verum