x:"as";y:"awash"
p0:{{z(1+&)\(1_ x)&(-1_ x)-y}/[&1+#y;x=\:y;1+!#x]}      /partial
p1:{{z(1+&)\(1_ x)&(-1_ x)-y}/[!1+#y;x=\:y;1+!#x]}      /total

x:"ctagc";y:"tgac" 100000 _draw 4                       /amino acid pattern
r0:{w+{&\z,(1+1_ x)&(-1_ x)-y}/[-w:!1+#y;x=\:y;1+!#x]}
r1:{(!1+#y)+{&\z,(1+1_ x)&(-1_ x)-y}/[&1+#y;x=\:y;1+!#x]}