# Managing assumptions

##### Contents

### About conjunctions

A term made by joining other terms with `&`

is called a
*conjunction*, and we consider all of those terms to be part of the
conjunction. For example `A & B & C & D`

is commonly viewed as a
conjunction of four terms rather than three separate conjunctions.

If we make all of the parentheses explicit, the conjunction

`A & B & C & D`

looks like this:

`(((A & B) & C) & D)`

In this form we can see that there are really three conjunctions
there, one for each occurrence of the `and`

operator.

If we rearrange the terms in these larger conjunctions, the same input
values still give the same result as before, so the conjunction is
equivalent (*equal*) to the original. For example

`(A & (B & (C & D))) == ((C & D) & (B & A))`

which is a tautology. Also, if a conjunction has multiple occurrences of the same term, the duplicates can be removed and the result is still equivalent to the original.