Which is easily seen to agree with the usual one,

lag /. $Substitutions // UReduce[#, SMMToMM -> True] & // Simplify

1/4 (f _ π^(ó  ))^2 (< ÷s _ μ _ 1(÷„)^† '6 ÷s _ μ _ 1(÷„) > + < ÷„^† '6 χ > + < χ^† '6 ÷„ >)

Lagrangian[ChPT2[2]]

1/4 (f _ π^(ó  ))^2 (< ÷„ '6 χ^† > + < χ '6 ÷„^† > + < ÷s _ μ(÷„) '6 ÷s _ μ(÷„)^† >)

Converted by Mathematica  (July 10, 2003)