The ornamental design for a displayscreen with a transitional graphical user interface, as shown and described.
FIG. 1 is a front view of a first image in a sequence for a display screen with a transitional graphical user interface;
FIG. 2 is a front view of a second image thereof; and,
FIG. 3 is a front view of a third image thereof.
The broken line showing of a display device in all views is for the purpose of illustrating environment and forms no part of the claimed design. The broken lines of text, numbers, icons, and boxes demonstrating portions of a graphical user interface displayed on the display screen in all views form no part of the claimed design. The areas filled in with speckles illustrate contrasting appearance, within parts in views of the graphical user interface displayed on the display screen, and form a part of the claimed design.
The appearance of the image transitions between images shown in FIGS. 1 through 3. The process or period in which one image changes to another forms no part of the claimed design.