Display screen or portion thereof with a graphical user interface

[0001]FIG. 1 is a front perspective view of a display screen or portion thereof with a graphical user interface, showing a first image in a sequence of the new design;

[0002]FIG. 2 is a front view showing the first image in the sequence thereof;

[0003]FIG. 3 is a front view showing a second image in the sequence thereof;

[0004]FIG. 4 is a front view showing a third image in the sequence thereof;

[0005]FIG. 5 is a front view showing the fourth image in the sequence thereof:

[0006]FIG. 6 is a front view showing a fifth image in the sequence thereof;

[0007]FIG. 7 is a front view showing a sixth image in the sequence thereof; and,

[0008]FIG. 8 is a front view showing a seventh image in the sequence thereof.

[0009]The inner broken line rectangle shows the display screen or portion thereof. Broken lines outside the display screen show the environment of a computing device. The remaining broken lines show portions of the graphical user interface. All broken lines form no part of the claimed design.

[0010]The appearance of the transitional image sequentially transitions between the images shown in FIGS. 2-8. The process or period in which one image transitions to another image forms no part of the claimed design.