# Logical operations¶

Disco has various standard operations for manipulating Boolean values.

Logical negation is written

`not`

; it inverts`true`

to`false`

and vice versa.Logical conjunction, aka AND, is written

`/\`

,`and`

, or`&&`

. It has the following truth table:`x`

`y`

`x /\ y`

F F F F T F T F F T T T Logical disjunction, aka OR, is written

`\/`

,`or`

, or`||`

. It has the following truth table:`x`

`y`

`x \/ y`

F F F F T T T F T T T T Logical implication, aka IF-THEN, is written

`->`

,`==>`

, or`implies`

. It has the following truth table:`x`

`y`

`x -> y`

F F T F T T T F F T T T Biconditional, aka “if and only if”, is written

`<->`

,`<==>`

, or`iff`

. It has the following truth table:`x`

`y`

`x <-> y`

F F T F T F T F F T T T