\starttext

x1 \emptylines[0] x1
x2 \emptylines[1] x2
x3 \emptylines[2] x3
x4 \emptylines[3] x4

x1 \par \emptylines[0] x1
x2 \par \emptylines[1] x2
x3 \par \emptylines[2] x3
x4 \par \emptylines[3] x4

\stoptext
