ADD and SUBTRACT (+ and -)

Software Customisation Reference Manual


Synopsis	number + number	-> number
	number ‑ number	-> number
	+ number	-> number
	- number	-> number
Description	Add or subtract two numbers. They can also be used as unary operators at the beginning of a parenthesised sub-expression.
Side Effects	Units are consolidated across add and subtract.
Example	1 + 2 -> 3.0 1 ‑ 2 -> 1.0 + 1 -> 1.0 - 1 -> -1.0
Errors	Floating point underflow.