Using parentheses with possessive pronoun

The following statements makes sense

It is impossible to doubt that you exist.

It is impossible to doubt that your mind exists.

However, if I were to add parentheses to the first statement which contain the information in the second, it becomes unclear as to which form of exist I should use.

It is impossible to doubt that you (or your mind) exist/exists.

Similarly and more confusingly:

You (or he) jump/jumps.