Modify the
In the execution this is an array write, but the logical definition is just a thin wrapper for update-nth:
Function:
(defun update-bits$ai (stobjs::i stobjs::v bitarr$a) (declare (xargs :guard (and (bitarr$ap bitarr$a) (integerp stobjs::i) (<= 0 stobjs::i) (< stobjs::i (bits$a-length bitarr$a)) (bitp stobjs::v) (stobjs::typep$ stobjs::v bit)))) (ec-call (update-nth stobjs::i (bfix stobjs::v) bitarr$a)))