Two dogs are running next to each other on a grassy hill.
The dogs are eating their food indoors.
The dogs are either eating or they are running but not both at the same time, and they are either on a grassy hill or are indoors, but not both simultaneously.
While the dogs are running next to each other on a grassy hill, how could be come for eating their food indoors. They may be either in th grassy hill or indoors.
running and eating cannot be done simultaneously. the dogs cannot be indoors and in the grassy hills at he same time.