reserve i,i1,i2,i3,i4,i5,j,r,a,b,x,y for Integer,
  d,e,k,n for Nat,
  fp,fk for FinSequence of INT,
  f,f1,f2 for FinSequence of REAL,
  p for Prime;
reserve fr for FinSequence of REAL;
reserve fr,f for FinSequence of INT;
reserve b,m for Nat;
reserve b for Integer;

theorem Th26:
  a mod p <> 0 implies Lege (a^2,p) = 1
proof
  assume a mod p <> 0; then
  not p divides a by INT_1:62; then
  not p divides a^2 by Th7; then
  a^2 mod p <> 0 by INT_1:62;
  hence thesis by Def3,Th9;
end;
