Editing boolean algebra/choose function

{| class="wikitable" style="float: right;"
! colspan="3" | Inputs !! Outputs
|-
! X !! Y !! Z !! Q
|-
| 0 || [[don't care|X]] || 0 || 0
|-
| 0 || [[don't care|X]] || 1 || 1
|-
| 1 || 0 || [[don't care|X]]|| 0
|-
| 1 || 1 || [[don't care|X]] || 1
|}
'''Choose function''' (or '''Ch Function''') is a [[Boolean function]] that represents a [[multiplexer|2:1 MUX]]. The choose function is frequently found in various [[cryptographic hash function]]s.

:<math>
f(x,y,z) =
\begin{cases}
y,  & \text{if $x$ = 1} \\[2ex]
z, & \text{if $x$ = 0}
\end{cases}
</math>


Which can be implemented as:
<math>
f(x,y,z) = (x \land y) \oplus (\bar x \land z)
</math>

== See also ==
* [[rotate left]] (ROL)
* [[rotate right]] (ROR)
* [[parity function]] (PAR)
* [[majority function]] (MAJ)
@@ Line 1: / Line 1: @@
-{{ba title|Choose Function (Ch)}}{| class="wikitable" style="float: right;"
+{| class="wikitable" style="float: right;"
 ! colspan="3" | Inputs !! Outputs
 |-
@@ Line 12: / Line 12: @@
 | 1 || 1 || [[don't care|X]] || 1
 |}
-'''Choose function''' (or '''Ch Function''') (sometimes '''if-then-else''' or '''ITE''') is a [[Boolean function]] that represents a [[multiplexer|2:1 MUX]]. The choose function is frequently found in various [[cryptographic hash function]]s.
+'''Choose function''' (or '''Ch Function''') is a [[Boolean function]] that represents a [[multiplexer|2:1 MUX]]. The choose function is frequently found in various [[cryptographic hash function]]s.
 :<math>
-\text{Ch}(x,y,z) =
+f(x,y,z) =
 \begin{cases}
-y,  & \text{ if } x = 1 \\
+y,  & \text{if $x$ = 1} \\[2ex]
-z, & \text{ if } x = 0
+z, & \text{if $x$ = 0}
 \end{cases}
 </math>
@@ Line 24: / Line 24: @@
 Which can be implemented as:
-::<math>
+<math>
-\text{Ch}(x,y,z) = (x \land y) \lor (\bar x \land z)
+f(x,y,z) = (x \land y) \oplus (\bar x \land z)
-</math>
-The xor version is sometimes more commonly in field such as [[cryptography]].
-::<math>
-\text{Ch}(x,y,z) = (x \land y) \oplus (\bar x \land z)
 </math>