For a Lagrange distribution of order zero we consider a quadratic integral
which has logarithmic divergence at the singular locus of the distribution.
The residue of the asymptotics is a Hermitian form evaluated in the space
of positive distributions supported in the locus. An asymptotic analysis of
the residue density is given in terms of the curvature form of the locus.
We state a conservation law for the residue of the impulse-energy tensor of
solutions of the wave equation which extends the classical conservation la
w in the geometrical optics.