Functions

Functions

The following arithmetic functions are predefined in PrologJ. A function will be evaluated if it occurs on the right hand side of is/2 or on either side of the arithmetic comparison operations (=:=, =\=, >, >=, < or =<).

Binary functions

Name	Description
`+`	Arithmetic addition.
`/\`	Bitwise logical and for integers.
`\/`	Bitwise logical or for integers.
`/`	Arithmetic division. Whether real number division is done even when the operands are integers depends on the setting of the $operator_single_slash flag.
`//`	Integer division.
`<<`	Bitwise left shift for integers.
`mod`	Integer modulus.
`**`	Arithmetic power.
`rem`	Integer remainder.
`>>`	Bitwise right shift for integers.
`-`	Arithmetic subtraction.
`*`	Arithmetic multiplication.

Unary functions

Name	Description
`abs`	Absolute value.
`atan`	Trignometric arctangent.
`\`	Bitwise logical complement for integers.
`ceiling`	Arithmetic ceiling. Result always an integer.
`cos`	Trignometric cosine.
`exp`	Arithmetic exponential.
`float`	Convert to a real.
`float_fractional_part`	Fractional part of a real number.
`float_integer_part`	Integer part of a real number - but still a real.
`floor`	Arithmetic floor. Result always an integer.
`log`	Natural logarithm.
`-`	Arithmetic negation.
`round`	Round to the nearest integer.
`sign`	Arithmetic signum - result always -1, 0, or 1.
`sin`	Trignometric sine.
`sqrt`	Arithmetic square root. Result always real.
`truncate`	Truncate to integer.

Zeroary functions

Name	Description
`e`	e - the base of natural logarithms.
`pi`	pi.
`random`	A random number in the range [0.0..1.0)