English of Core Text: Rabbi Meir says: Any condition that is not like the condition of the children of Gad and the children of Reuven is not a [valid] condition; and that is what is written “If you do well... and if you do not do well.”
On the daf / in context: The double formulation (positive and negative) of the condition in our verse is cited as a model of a complete tenai.
Type of Learning: Custom (form of a valid condition)What Is Learned: A complete condition must state both the positive and the negative, as in “if you do well / if you do not do well.”