toplevel "SPARE";
"SPARE" wsp "PC" "FSC" "SSC";
"PC" or "A" "B";
"B" or "C" "D" "E";
"FSC" lambda=0.5 dorm=0.3;
"SSC" lambda=0.5 dorm=0.3;
"A" lambda=0.5 dorm=0.3;
"C" lambda=0.5 dorm=0.3;
"D" lambda=0.5 dorm=0.3;
"E" lambda=0.5 dorm=0.3;