Numbers

An arithmetic expression is a term that is built from numbers, variables, and the arithmetic functions. An expression must be ground when it is evaluated.

• Exp1 is Exp2: The term Exp2 must be a ground expression, and Exp1 must either be a variable, or a ground expression. If Exp1 is a variable, then the call binds the variable to the result of Exp2. If Exp1 is a non-variable expression, then the call is equivalent to Exp1 =:= Exp2.

• X =:= Y: The expression X is numerically equal to Y.

• X =\= Y: The expression X is not numerically equal to Y.

• X < Y: The expression X is less than Y.

• X =< Y: The expression X is less than or equal to Y.

• X > Y: The expression X is greater than Y.

• X >= Y: The expression X is greater than or equal to Y.

The following functions are provided:

• X + Y: addition.
• X - Y: subtraction.
• X * Y: multiplication.
• X / Y: division.
• X // Y: integer division, the same as in C.
• X div Y: integer division, rounded down.
• X mod Y: modulo (X-integer(floor(X/Y))*Y).
• X rem Y: remainder (X-(X//Y)*Y).
• X /> Y : integer division (ceiling(X/Y)).
• X /< Y : integer division (floor(X/Y)).
• X ** Y : power.
• -X : sign reversal.
• X » Y : bit shift right.
• X « Y : bit shift left.
• X /\ Y : bitwise and.
• X \/ Y : bitwise or.
• \ X : bitwise complement.
• X xor Y: bit wise xor.
• abs(X) : absolute value.
• atan(X) : arctangent(the argument is in radians).
• atan2(X,Y) : principal value of the arctangent of Y / X.
• ceiling(X) : the smallest integer that is not smaller than X.
• cos(X) : cosine (the argument is in radians).
• exp(X) : natural antilogarithm, e^X.
• integer(X) : convert X to an integer.
• float(X) : convert X to a float.
• float_fractional_part(X) : float fractional part.
• float_integer_part(X) : float integer part.
• floor(X) : the largest integer that is not greater than X.
• log(X) : natural logarithm, log_eX.
• log(B,X) : logarithm in the base B, log_BX.
• max(X,Y) : the maximum of X and Y (not in ISO).
• max(L) : the maximum of the list of elements L (not in ISO).
• min(X,Y) : the minimum of X and Y (not in ISO).
• min(L) : the minimum of the list of elements L (not in ISO).
• pi : the constant pi (not in ISO).
• random : a random number (not in ISO).
• random(Seed) : a random number that is generated by using Seed (not in ISO).
• round(X) : the integer that is nearest to X.
• sign(X) : sign (-1 for negative, 0 for zero, and 1 for positive).
• sin(X) : sine (the argument is in radians).
• sqrt(X) : square root.
• sum(L) : the sum of the list of elements L (not in ISO).
• truncate(X) : the integer part of X.