Changes in Version 1.1-0 o The CITATION was incorrect and is fixed now. Changes in Version 1.1-0 o All methods returning "formula" or "Formula" objects now preserve the environment of the originally supplied object by default. o The default and formula methods of as.Formula() methods now also take an env argument. Changes in Version 1.0-1 o Added a terms = FALSE argument to model.part() method for "Formula" objects. This can be leveraged when processing multiple offsets. For example for y ~ x + offset(o1) | z + offset(o2). See ?model.part for a worked example. Changes in Version 1.0-0 o package now published in Journal of Statistical Software, see http://www.jstatsoft.org/v34/i01/ and citation("Formula") within R. o added an all.equal() method for "Formula" objects that produces more intelligible output in case the result is not TRUE. o fixed an error of the update() method for "Formula" objects without LHS. Changes in Version 0.2-0 o Major revision (not fully backward compatible) to enable support for multiple responses and multiple parts on the right-hand side such as y1 | y2 ~ x y1 + y2 ~ x1 + x2 | z1 y ~ u1 + u2 | v1 | x1 + x2 and combinations of these. o Formula objects now consist of the original formula plus two attributes "lhs" and "rhs" that contain the parts of the decomposed left- and right-hand side, respectively. o Most methods take arguments "lhs" and "rhs" which allow selection of the desired parts on the left- and right-hand side respectively, e.g., in a model.frame() or model.matrix(). o The previous arguments response = TRUE/FALSE and part = "first"/"second"/"both" were not flexible enough anymore and have been deprecated. Use the streamlined lhs/rhs arguments instead. o vignette("Formula", package = "Formula") illustrates usage of the tools provided by the package and explains the ideas underlying its implementation. Changes in Version 0.1-3 o added CITATION file. o added a has.intercept function with methods for formula and Formula objects. o change the default value for model.frame.Formula: "both" for a two-part formula and "first" otherwise. Changes in Version 0.1-2 o Bug fix: as.Formula() failed for very long formulas. Changes in Version 0.1-1 o First CRAN release of package "Formula" for extended formula processing. This package is still under development and the interface might change in future versions. o Currently, this enables processing of formulas such as y ~ x1 + x2 | z1 + z2 + z3 with two parts on the right hand side. o Generalization to further formulas are planned (i.e., not implemented yet), e.g., y1 + y2 ~ x1 + x2 + x3 y ~ x1 + x2 | u1 | v1 + v2 + v3 | ... i.e., multiple responses and multi-part formulas.