Please help me simplify this! the exclamations marks represent NOT
B! C! D! + A! B C! D! +A B C! D! + A! B! C D + A B! C D + A! B! C D! + A B C D! + A B! C D!
B! C! D! + A! B C! D! +A B C! D! + A! B! C D + A B! C D + A! B! C D! + A B C D! + A B! C D!