Option Explicit
Sub Plot()
Dim x1%, y1%, x2%, y2%, x3%, y3%
Dim A%, B%, C%
'coordonnées plot A
For x1 = -76 To -72
Range("a1").Value = x1
For y1 = -1 To 1
Range("a2").Value = y1
'coordonnées plot B
For x2 = -76 To -72
Range("b1").Value = x2
For y2 = -1 To 1
Range("b2").Value = y2
'coordonnées plot C
For x3 = -76 To -72
Range("c1").Value = x3
For y3 = -1 To 1
Range("c2").Value = y3
A = Cells(x1, y1)
B = Cells(x2, y2)
C = Cells(x3, y3)
If A <> B And A <> C And B <> C Then
MsgBox "A différent de B et de C"
End If
Next
Next
Next
Next
Next
Next
End Sub