New arithmetic functions programmed in MINERVA are used exactly as built in functions.

This allows both functional and relational notations for arithmetic expressions.

MINERVA predicates for arithmetic evaluation, e.g. is/2 used on a function like "Result = f(A,...,N)" will search for a predicate "f(A,...,N,Result)".

Thus arithmetic in MINERVA becomes easier to read and uses aggresive variable hiding.

% example: compute the cost for industrial urethane foam

% notation as relations
a(Price) :-
	height(H), width(W), depth(D),
	unit_price_per_volume(U),
	Price is H * W * D * U.

% notation as functions

b(Price) :-
	Price is height * width * depth * unit_price_per_volume.

% uniform notation of functions resp. data base

height(6).
depth(38).
width(75).
unit_price_per_volume(0.01).

Here is the result for the above program:

?- a(Price).

Price   = 171.0 

yes

?- b(Price).

Price   = 171.0 

yes

?-