export function has_units(x){
if(A.iscons(x)){
return has_units(A.car(x)) || has_units(A.cdr(x))
}else if(is_unit(x)) {
return true
}
return false
}
function* listify(cons){
while(cons.k == A.CONS){
yield A.car(cons)
cons = A.cdr(cons)
}
}