In the IDE this code does not error but does not behave correctly when ANDing a Boolean with another Boolean or a True or False literal value. It immediately exits the IF block without executing the Msgbox statement. It does throw an error if you try to compile. OR doesn't work either but NOT() seems to be OK
B4X:
Sub test
Dim b As Boolean
If b = False Then
b = b AND True
Msgbox(b)
End If
End Sub