AIG operations for carrying out substitutions, compositions, and partial evaluations.

- Aig-partial-eval
`(aig-partial-eval x env)`evaluatesx , an AIG, under the partial environmentenv , producing a new AIG as a result.- Aig-restrict
`(aig-restrict x sigma)`performs variable substitution throughout the AIGx , replacing any variables bound insigma with their corresponding values.- Aig-compose
`(aig-compose x sigma)`performs variable substitution throughout the AIGx ,**unconditionally**replacing every variable inx with its binding insigma .- Aig-restrict-alist
`(aig-restrict-alist x sigma)`substitutes into an AIG Alist (an alist binding keys to AIGs).- Aig-partial-eval-alist
`(aig-partial-eval-alist x env)`partially evaluates an AIG Alist (an alist binding keys to AIGs).- Aig-compose-alist
`(aig-compose-alist x sigma)`composes into an AIG Alist (an alist binding keys to AIGs).- Aig-restrict-alists
`(aig-restrict-alists x sigma)`substitutes into a list of AIG Alists.- Aig-compose-alists
`(aig-compose-alists x sigma)`composes into a list of AIG Alists.- Aig-restrict-list
`(aig-restrict-list x sigma)`substitutes into a list of AIGs.- Aig-partial-eval-list
`(aig-partial-eval-list x env)`partially evaluates a list of AIGs.- Aig-compose-list
`(aig-compose-list x sigma)`composes into a list of AIGs.