toplevel "A";
"A" and "B" "C";
"B" wsp "I" "J";
"C" wsp "K" "L";
"I" lambda=0.5 dorm=0.3;
"J" lambda=0.5 dorm=0.3;
"K" lambda=0.5 dorm=0.3;
"L" lambda=0.5 dorm=0.3;