Changes in version 2025.1.0                       

    o   Major rewrite to properly handle complex formula terms
	including:
	
	  • Factor variables with multiple levels
	
	  • Interaction terms (e.g., x1:x2, x1:factor)
	
	  • Polynomial terms (e.g., I(x^2))
	
	  • Complex interactions with polynomials (e.g., I(x^2):factor)
	
	  • Log transformations with interactions (e.g., log(x):factor)
	
	  • Three-way and higher-order interactions

    o   Fixed bug where null model returned incorrect log-likelihood.
	Previously, when the null model was selected, the function
	returned the log-likelihood of the last non-null model instead
	of the actual null model log-likelihood (loglik.null).

    o   Eliminated deprecation warning related to formula.character()
	for formulas with length > 1.

    o   Improved term handling using the assign attribute from
	model.matrix() to correctly identify which columns belong to
	which terms.

    o   Added helper functions for safer formula manipulation:
	
	  • safe_as_formula(): Safely converts various inputs to
	    formula objects
	
	  • safe_drop_term(): Drops terms by reconstructing formula
	    from term labels
	
	  • safe_add_term(): Adds terms by reconstructing formula
	    string

    o   Replaced regex-based column matching with proper assign
	attribute tracking, fixing issues where variable names
	contained other variable names as substrings.

    o   Added explicit namespace prefixes (stats::, cmprsk::) for CRAN
	compliance.

                Changes in version 2015-2.1 (2015-02-23)                

    o   Corrected a bug in backward selection procedure in how
	scope.min was checked to terminate the selection procedure.

    o   Added checks to make sure that scope.min formula input is
	correct.

    o   Simplified how standard error was computed.

    o   Fixed a bug related to outputting results in forward selection.

               Changes in version 2014-07.16 (2014-07-17)               

    o   Corrected a bug in backward selection procedure when one
	variable name is contained in another variable name (e.g.,
	"Mitosis" and "AtyMitosis").

    o   Corrected a bug in forward selection procedure when an
	as.factor() variable is to be added to the model.