Boolean data type has two possible truth values to represent logic.
📦 Package, :blue_book: Wiki.

Here is my implementation of digital logic gates in software. That includes the basic gates not, and, or, xor; their complements nand, nor, xnor; and 2 propositional logic (taught in discrete mathematics) gates imply, eq; and their complements nimply, neq. There is also a multiplexer, called select, and a true counter, called count. count can help you make custom gates, such as an alternate concept of xnor which returns true only if all inputs are the same (standard xnor returns true if even inputs are true). All of them can handle upto 8 inputs.

parse is influenced by "boolean" package, and is quite good at translating string to boolean. It can also handle double negatives, eg. not inactive. You know the and of 2-inputs, but what of 1-input? What of 0? And what of the other gates? I answer them here.

Stability: Experimental.

import Boolean exposing (..)

parse "1"
parse "truthy"
parse "not off"
-- True

parse "not true"
parse "inactive"
parse "disabled"
-- False

imply True False
-- False

eq False False
-- True

xor3 True True True
-- True

select3 1 True False True
-- False         ^

count3 True True False
-- 2    ^    ^

Index

Function	Action
parse	Converts string to boolean.
not	Checks if value is false.
and	Checks if all values are true.
or	Checks if any value is true.
xor	Checks if odd no. of values are true.
nand	Checks if any value is false.
nor	Checks if all values are false.
xnor	Checks if even no. of values are true.
eq	Checks if antecedent ⇔ consequent.
neq	Checks if antecedent ⇎ consequent.
imply	Checks if antecedent ⇒ consequent.
nimply	Checks if antecedent ⇏ consequent.
select	Checks if ith value is true.
count	Counts no. of true values.