P-complete

Circuit Evaluation over Monoids (CEM)

Input

A finite monoid $(M, \oplus, 1)$ containing a nonsolvable group; an encoding $\overline{\alpha}$ of a circuit $\alpha$, whose gates are of type $\oplus$, inputs $x_1, \ldots, x_n \in M$, and designated output $y$.

Problem

Does $\alpha$ evaluate to $y$ on input $x_1, \ldots, x_n$?

Definitions

See CVP. Set $M$ is finite, $\oplus$ is an associative binary operation on the elements of $M$, and $1$ acts as an identity element.

Status

$\P$-complete (Beaudry, McKenzie, and Péladeau [1]).

Remarks

The reduction to show hardness is from CVP. If $M$ is solvable the same problem is in $\mathsf{DET}$, the class of problems $\NC^1$ Turing reducible to computing integer determinants.

References

  1. M. Beaudry, P. McKenzie, and P. Péladeau (1992). Circuits with monoidal gates.
  2. Greenlaw, R., Hoover, H. J., and Ruzzo, W. L. (1995). Limits to Parallel Computation: P-Completeness Theory. Oxford University Press. Problem A.1.13.