Not

not is a keyword unary operator that returns the logical negation of its operand. In its simplest usage, not true is equal to false, and not false is equal to true.

Numeric Operands

In detail, for any numeric operand x, the result of not x depends on the absolute value of x. The full truth table for not with numeric operands is shown below.

Range of abs(x)	not x
abs(x) <= 0	1
0 < abs(x) < 1	1 - x
abs(x) >= 1	0

This is consistent with MiniScript’s support for fuzzy logic. If interpreted as probability, then if p is the probability of an event happening, not p is the probability of that event not happening.

Non-Numeric Operands

When used with types other than numbers, not returns 1 (true) if the given value is “empty”, and 0 (false) if the operand is “not empty”, as shown below.

Type of x	Characteristic of x	not x
string	empty, i.e. x.len == 0	1
string	non-empty, i.e. x.len > 0	0
list	empty, i.e. x.len == 0	1
list	non-empty, i.e. x.len > 0	0
map	empty, i.e. x.len == 0	1
map	non-empty, i.e. x.len > 0	0
function	any	0
null	(N/A)	1