Arithmetics¶

Numbers¶

object : arith-obj

We can use numbers as modifiers in predicates. To do so, we must define the modifiers of verbs with the term number. At the moment, numbers are simply floats, but this may change.

a thing can has_position x a number, y a number.

With this, we can say something like thing1 [has_position x 1, y 2]..

Arithmetic operations¶

arith-obj : NUMBER
          | LCURL arith-operation RCURL

arith-operation : arith-operand arith-operator arith-operation
                | arith-operand arith-operator arith-operand

arith-operand : NUMBER
              | VAR
              | LPAREN arith-operation RPAREN

arith-operator : PLUS
               | MINUS
               | MULTIPLICATION
               | DIVISION

instant : arith-obj

We can use arithmetic operations in the consecuences of rules, both in place of number modifiers and in place of instants. We enclose the operations in outermost curly brackets, and any internal grouping id done with parentheses. The available operators are sum +, subtraction -, multiplication * and division /. For example, {4 + (N1 - N2)}.

Arithmetic conditions¶

condition : arith-condition

arith-condition : LCURL arith-predication RCURL

arith-predication : arith-operand arith-predicate arith-operand

arith-predicate : LT
                | GT
                | EQ
                | NEQ

We can specify arithmetic conditions. We do so enclosing the condition in curly brackets. The available predicates are less than <, greater than >, equals =, and not equals <>. For example { I1 < 33 };. We can use instant variables in the condition, as well as number variables. We can also use arithmetic operations within arithmetic conditions.