About the image stack
1.Initial stack
When several images are loaded in G’mic, they are ordered in a stack. It is then possible to refer to them by using either positive (starting from the first image as [0]) or negative numbers (starting from the last image as [-1]).
For example, if 3 images A, B and C are loaded:
gmic A.png B.png C.png
It creates a stack that you can picture like that:
You can refer to A as image [0] or image [-3], B as [1] or [-2] and C as [2] or [-1]. So both commands below do exactly the same thing, they display B:
gmic A.png B.png C.png -display[1] gmic A.png B.png C.png -display[-2]
2.Command with one dash
If, in your command line, you add an instruction using a single dash, it replaces the images to which the instruction applies by the result. Thus, to split the different channels of B, the 2 commands below could be used is added to our first command:
gmic A.png B.png C.png -split[1] c gmic A.png B.png C.png -split[-2] c
And they would modified the stack as shown below:
As you can see, the image A is still [0], but not [-3] anymore, it has become [-5].
3.Command with two dashes
To keep the original image, instruction are called using 2 dashes. The original image is indeed kept in place and the result is added at the end of the stack.
So commands below:
gmic A.png B.png C.png --split[1] c gmic A.png B.png C.png --split[-2] c
would modify the stack as below:
4.Stack order matters, not invoking order
When you apply a command to several images, sometimes, order matters. But be careful, stack order matters, not invoking order.
For example, both commands below have the same result:
gmic A.png B.png -append[0,1] y gmic A.png B.png -append[1,0] y
If you want to apply your command in another order, you have to play with the image stack, such as:
gmic A.png B.png -reverse[0,1] -append[0,1] y
or
gmic A.png B.png -move[1] 0 -append[1,0] y
G'mic tutorials 
How i could have missed this till now ?
thank , finally i diciver because layers(images) were never were i expected…i was counting with negative number from the top
(So i tought that 0 was -1 and so on..)
the first image cleared immediatly and the text did the rest,
thank again