Tools to using fonts other than the standard PostScript fonts.
    This package makes it easy to use system TrueType fonts and with PDF or
    PostScript output files, and with bitmap output files in Windows. extrafont
    can also be used with fonts packaged specifically to be used with, such as
    the fontcm package, which has Computer Modern PostScript fonts with math
    symbols.

It is meant to be used with the 'extrafont' package. The 'extrafont' package contains the code to install and use fonts, while the 'extrafontdb' package contains the font database.

Provide estimation and data generation tools for new multivariate frailty models.
             This version includes the gamma, inverse Gaussian, weighted Lindley, Birnbaum-Saunders,
	     truncated normal, mixture of inverse Gaussian, mixture of Birnbaum-Saunders, 
             generalized exponential and Jorgensen-Seshadri-Whitmore as the distribution for
             frailty terms. For the basal model, it is considered a parametric approach based 
             on the exponential, Weibull and the piecewise exponential distributions as well as a 
             semiparametric approach. For details, see Gallardo et al. (2024) <doi:10.1007/s11222-024-10458-w>,
             Gallardo et al. (2025) <doi:10.1002/bimj.70044>, Kiprotich et al. (2025) <doi:10.1177/09622802251338984>
             and Gallardo et al. (2025) <doi:10.1038/s41598-025-15903-y>.

Speed up common tasks, particularly logical or
  relational comparisons and routine follow up tasks such as finding the
  indices and subsetting. Inspired by mathematics, where something like:
  3 < x < 6 is a standard, elegant and clear way to assert that
  x is both greater than 3 and less than 6
  (see for example <https://en.wikipedia.org/wiki/Relational_operator>),
  a chaining operator is implemented. The chaining operator, %c%,
  allows multiple relational operations to be used in quotes on the right
  hand side for the same object, on the left hand side.
  The %e% operator allows something like set-builder notation 
  (see for example <https://en.wikipedia.org/wiki/Set-builder_notation>) 
  to be used on the right hand side.
  All operators have built in prefixes defined for all, subset, and which
  to reduce the amount of code needed for common tasks, such as return those
  values that are true.