=

(= &rest numbers)

Returns t if all of its arguments are numerically equal, else nil. It is variadic and compares by numeric value across types, so an integer and an equal float or ratio compare equal (unlike eql). A float beside an exact number compares exact values -- the float counts at its precise binary value, so a ratio that merely rounds to the float is not equal. With a single argument it returns t once the argument is checked: a non-number signals a type-error.