 reserve i,j,k,k0,m,n,N for Nat;
 reserve x,y for Real;
 reserve p for Prime;

theorem ::SqrtLe:
  0 <= x & 0 <= y & x <= y^2 implies sqrt x <= y
  proof
    assume A1: 0 <= x & 0 <= y & x <= y^2; then
    sqrt x <= sqrt y^2 by SQUARE_1:26;
    hence thesis by A1,SQUARE_1:22;
  end;
