let bool_array_and_bycase bc_arr1 bc_arr2 =
if Array.length bc_arr1 <> Array.length bc_arr2 then
assert false;
let res=Array.make
(Array.length bc_arr1) (Array.make (Array.length bc_arr1.(0)) false)
in
Array.iteri
(fun case b1 -> res.(case)<-bool_array_and b1 (bc_arr2.(case)))
bc_arr1;
res