Logical Operators

logical-expression:
        expression && expression
        expression and expression
        expression || expression
        expression or expression
        ! expression
        not expression

EDEN operates in 3-value logic (true, false and @). Any non-zero value means true; zero means false. In addition to the lazy operators (as in C, left-to-right evaluation, the second operand is evaluated only if necessary), eager operators - and, or, not - are also defined. Notice that the truth tables for the lazy and the corresponding eager operators are not identical.

`@ && @ = @`	`@ and @ = @`	`@ \|\| @ = @`	`@ or @ = @`
`@ && F = @`	`@ and F = @`	`@ \|\| F = @`	`@ or F = @`
`@ && T = @`	`@ and T = @`	`@ \|\| T = @`	`@ or T = @`
`F && @ = F`	`F and @ = @`	`F \|\| @ = @`	`F or @ = @`
`F && F = F`	`F and F = F`	`F \|\| F = F`	`F or F = F`
`F && T = F`	`F and T = F`	`F \|\| T = T`	`F or T = T`
`T && @ = @`	`T and @ = @`	`T \|\| @ = T`	`T or @ = @`
`T && F = F`	`T and F = F`	`T \|\| F = T`	`T or F = T`
`T && T = T`	`T and T = T`	`T \|\| T = T`	`T or T = T`

`! @ = T`	`not @ = @`
`! F = T`	`not F = T`
`! T = F`	`not T = F`

Truth Tables for operators: &&, and, ||, or, !, not.