You can package Y(1) into a one element container. For Ref or tuple are common choices:
f.( [X(1),X(1)], Ref(Y(1)) )
f.( [X(1),X(1)], (Y(1),) )
You can package Y(1) into a one element container. For Ref or tuple are common choices:
f.( [X(1),X(1)], Ref(Y(1)) )
f.( [X(1),X(1)], (Y(1),) )