Arithmetic operators and their availability:

level	Operator	Integer	Float	String	Boolean
1	'--'	yes	no	no	no	Decremention (unary; prefix and suffix version)
1	'++'	yes	no	no	no	Incremention (unary; prefix and suffix version)
2	'*'	no	no	no	no	Pointer dereferencing (unary)
3	'^'	yes	yes	no	no	Potentiation
4	'*'	yes	yes	no	no	Multiplication
4	'/'	yes	yes	no	no	Division
4	'%'	yes	no	no	no	Modulo
5	'+'	yes	yes	yes	no	Addition
5	'-'	yes	yes	no	no	Substraction
6	<	yes	yes	yes	no	Less than
6	<=	yes	yes	yes	no	Less or equal
6	=	yes	yes	yes	no	equal
6	>	yes	yes	yes	no	greater or equal
6	>=	yes	yes	yes	no	greater than
6	<>	yes	yes	yes	no	not equal
7	AND	yes	no	no	yes	AND
8	OR	yes	no	no	yes	OR
8	XOR	yes	no	no	yes	XOR
9	?:	yes	yes	yes	yes	conditional evaluation

Operators with a lower level are evaluated first.
Operators on the same level are evaluated from left to right.
The result of the comparisn operators is boolean.
The boolean negation is done by the function NOT!()
Note: The modulo-operator is at the same time a type characteristic (Integer). Therefore a blank must always stand after previous identifiers if used as modulo-operator.