Booleans and Relations

# is a special character in Scheme. #t and #f must be typed without any spaces between # and t or f. In the full Scheme language, some other letters or symbols can follow # with special meanings, but most characters following # result in a syntax error.

Like the arithmetic operations, the test operations can take more than two arguments. For example, (< 1 2 3) is legal Scheme notation for ``1 < 2 and 2 < 3.'' The and and or operators also take any number of arguments. The not operation always takes one argument.