--- /dev/null
+digraph ww_sc_fence_second_collapse {
+margin=0
+ranksep=.3;
+
+N1 [label="A: v.store(1)", shape=none];
+N2 [label="X: fence(seq-cst)", shape=none];
+//N3 [label="Y: fence(seq-cst)", shape=none];
+N4 [label="B: v.store(2, seq-cst)", shape=none];
+N5 [style=invis, shape=point];
+
+//N1 -> N4 [label="mo", color="#00aa00", style=dashed, penwidth=3];
+N2 -> N4 [label="sc", color=purple];
+N1 -> N2 [label="sb", color=blue, weight=100];
+N2 -> N5 [style=invis];
+N5 -> N4 [style=invis];
+{rank=same; N4 N5}
+}