The printed representation of a ratio is a pair of integers separated by a slash ( / ). A ratio can also be written as a proper fraction by following an integer part with + or - (matching the sign of the integer) and a ratio. No intermediate whitespace is permitted within a ratio literal. Here are some examples:
75/33 1/10 1+1/3 -10-1/7

More information on ratios can be found in Rational numbers.