# lfl 2.1.1
* fixed the minimum required version of R to 3.6


# lfl 2.1.0
* the result of algebra() is now an S3 class, implemented print.algebra()
* added involutive negation to algebra()$ni
* added nelson(), lowerEst() handlers of NA for algebra()
* added print() method for linguistic contexts
* added negated=FALSE argument to the lingexpr() function
* implemented bi-residuum of the dragonfly algebra
* implemented order operation of the dragonfly and lowerEst algebras
* added sugeno()
* added fuzzy quantifiers
* deprecated some arguments of the compose() function
* removed deprecated functions: lcut3(), lcut5()


# lfl 2.0.1
* added support for percentual quantifiers in compose()
* documentation spell-check

