let X be set ; :: thesis: for SF being Subset-Family of X holds basis_Pervin_uniformity SF is V288()
let SF be Subset-Family of X; :: thesis: basis_Pervin_uniformity SF is V288()
now :: thesis: for x, y being set st x in basis_Pervin_uniformity SF & y in basis_Pervin_uniformity SF holds
x /\ y in basis_Pervin_uniformity SF
end;
hence basis_Pervin_uniformity SF is V288() ; :: thesis: verum