now :: thesis: for b, c being Real st b |^ n = a & b > 0 & c |^ n = a & c > 0 holds
not b <> c
let b, c be Real; :: thesis: ( b |^ n = a & b > 0 & c |^ n = a & c > 0 implies not b <> c )
assume that
A35: b |^ n = a and
A36: b > 0 and
A37: c |^ n = a and
A38: c > 0 and
A39: b <> c ; :: thesis: contradiction
per cases ( b > c or c > b ) by A39, XXREAL_0:1;
end;
end;
hence for b1, b2 being Real holds
( ( a > 0 & b1 |^ n = a & b1 > 0 & b2 |^ n = a & b2 > 0 implies b1 = b2 ) & ( a = 0 & b1 = 0 & b2 = 0 implies b1 = b2 ) ) ; :: thesis: verum