USING
curfile.action = USING;
case USING:
curfile.action = USING;
curfile.action = USING;
if (curfile.action == USING) {
curfile.action = USING;
using_opt(U) ::= USING LP idxlist(L) RP. {U = L;}
cmd ::= COPY orconf(R) nm(X) dbnm(D) FROM nm(Y) USING DELIMITERS STRING(Z).
key_opt(A) ::= USING ids(X). { A = X; }