A reported interval should be compared by endpoints, not by prose. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.
highlighted = computed this step
The first drift interval matches the resolution interval
Drift gives 14 through 16. Resolution gives 14 through 16. Exact match bit is 1.
[14,16]=[14,16]
A wider resolution interval can cover the drift interval
Drift gives 16 through 18. Resolution gives 15 through 19. Cover bit is 1.
[15,19]⊃[16,18]
A second wide interval also covers a lower signal band
The third drift interval is 11 through 13; the resolution interval is 10 through 14. Cover bit is 1.