Syntax: @AND(argumentlist)
argumentlist = any combination of numbers, cells, or ranges
@AND returns 1 if all arguments are 1; 0 if any argument is 0; otherwise -1 (unknown).
Examples:
A1=1, B1=1, C1=0, D1=0, E1=1 and A2=24
@AND(A1, B1) = 1
@AND(A1..E1) = 0
@AND(A1..A2) = -1