In reply to alexd555:
- logic is a scalar 4-state binary digit with the possible values 1’b0, 1’b1, 1’bx, or 1’bz
- bit is a scalar 2-state binary digit with the possible values 1’b0 or 1’b1
- integer is a signed integral vector made from a packed array of 32 logic digits.
You need a packed array of at least 3 digits to hold the decimal value 4.