of this observable on $k$. On the other hand, when $H_2$ is included, the slope is markedly steeper than at NLO. The general agreement between predicted and fitted slope is astounding, and actually quite stable against variation of the fit range or of the two cutoffs $\Lambda_1$ and $\Lambda_2$. Only the LO numbers are somewhat sensitive, and only to the upper limit [@improve3body].

It is somewhat surprising that the slope increases by two units from NLO to [N${}^{2}$LO]{} when one includes $H_2$. One would have expected the change from each order to the next to be by only one unit. This may stem from the “partially resummed formalism” used at that time. Since that resums some higher-order contributions, it may be worth revisiting this issue with J. Vanasse’s method to determine higher-order corrections in “strict perturbation” [@Vanasse:2013sda]. But we will see in the notes on “Assumptions of the Expansion” in Sect. \[sec:notesofnote\] that a fitted slope which is larger than predicted does not invalidate the power counting – the converse does.

Finally, one reads off a rough value of ${\overline{\Lambda}_{\slashed{\pi}}}\approx[120\dots150]\;{\ensuremath{\mathrm{MeV}}}$ as the region where the fitted lines coalesce. This is not in disagreement with the breakdown scale expected of [EFT($\slashed{\pi}$)]{}.

