Rudi Gaelzer wrote: > What I want and need is a means to implement the math ENVIRONMENTS defined > by the mathtools package and that are not explicitly supported by LyX. > Specifically for multiline equations. LyX supports the standard AMS inner > and outer environments, such as align (outer) and aligned (inner). > However, multline is only an outer env in the standard AMSmath. The > mathtools pack defines the corresponding inner multlined environment, and > it seems that there is no way to use it other than ERTing the math input > (see attached file). I guess the same tweak can be applied in order to use > the other new environments defined by mathtools, such as dcases, rcases, > drcases, psmallmatrix, bsmallmatrix, etc.
Unfortunately it is not possible to use unsupported math environments in LyX without putting the whole formula in ERT or do some advanced macro tricks. The reason for this is that the native LyX format for math formulas is LaTeX. This is implemented in such a way that _everything_ is parsed, so it is not possible to have a true ERT in mathed. The parser supports unknown commands somewhat (so they appear in red), but not environments. This is of course a problem and needs to be fixed, but up to now nobody worked on it. If it does not exist already please file a bug report at http://www.lyx.org/trac/wiki/BugTrackerHome to support unknown environments in math. Georg