Perform arithmetic on shell variables.

Syntax letexpression[expression]

Each `expression` is an arithmetic expression to be evaluated. If the last `expression` evaluates to 0, `let`

returns 1; otherwise 0 is returned.

`let' is a bash builtin command.

*"Arithmetic is being able to count up to twenty without
taking off your shoes" ~ Mickey
Mouse*

**Related:**

expr - Evaluate expressions

eval - Evaluate several commands/arguments

test - Evaluate a conditional expression