12.0 0.0 0.456 3.14159_26 --real literals
base # based_numeral [.based_numeral] # [exponent]
extended_digit {[underline] extended_digit}
16#E#E1 2#1110_0000# --integer literals of value 224
16#F.FF#E+2 2#1.1111_1111_1110#E11 --real literals of value 4095.0