ADD and SUBTRACT (+ and -)

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 parenthesized sub-expression.

Side Effects

Units are consolidated across add and subtract and the result is returned in current units of the physical quantity, for example when current distance units are inches

q (1ft + 100mm) will return 15.9in

If only one value has a unit qualifier the other is assumed to be in current units of that physical quantity for example:

q (1ft + 100 ) will return 112in

If the two values have conflicting units a warning is issued and a value is returned with no units assuming both values are in the database units of their respective quantities which is mm and Kg in the example:

q (1ft + 1kg ) will return 305.8

Example

1 + 2 -> 3.0

1 ‑ 2 -> 1.0

+ 1 -> 1.0

- 1 -> -1.0

Errors

Floating point underflow.