x1 is the differintegral of x2 with respect to x3 of order x4, with differintegration being according to definition/specification or of type x5.
All integrals are indefinite. Definition of which differintegral operator is being used is context-dependent if not specified explicitly by x5. Dimensionality of x1 and x2 may be similarly specified. Output x1 is a function, not a value (that is, it is some f rather than f(x)); it must be specified/restricted to a value in order to be a value; thus, output may be g' but not g'(a) for some a; similarly, definite integrals and integration constants must be defined with additional effort. x2 is likewise a function. If x2 is univariate, then x3 defaults to that input/variable; when x2 is physical, without context, time will probably usually but not necessarily be assumed as the default of x3 (but may be made explicit by "temci zei salrixo" or merely "temsalri"). Positive values of x4 are integrals, negative values are derivatives, and zero is identity; at the least, any real value may be supplied for x4; x4 has no default value. Useful for making lujvo for physics, for specifying career/total/sum versus peak/instantaneous value, for distinguishing between instantaneous versus average values/quantities, for specifying rates, generalized densities (including pressure), "per" for smooth quantities, etc. See also: "salri" (synonymous gismu).