أداء الفرضين بتيمم واحد
Performing two obligatory prayers with one tayammum.
If tayammum produces a recognized state of purity, that state need not terminate merely because one obligatory prayer has been completed. Under the Hanafi analysis, another obligatory prayer can follow without a new tayammum unless an invalidating cause has arisen.
A theory treating tayammum only as permission for a particular obligation yields different restrictions. The practical disagreement flows from the underlying definition of tayammum.