namespace lyx {
+class MetricsBase;
/* The TeXbook, p. 158:
*
docstring const class_to_string(MathClass);
+void update_class(MathClass & mc, MathClass const prev, MathClass const next);
+
+int class_spacing(MathClass const mc1, MathClass const mc2,
+ MetricsBase const & mb);
} // namespace lyx