remove uses of as-int
simplify intermediate string representation
functions for 2d grid alignment
presentation-type and render-method for matrices
move from lazy-array to infinite-sequence
remove obsolote package (pre math-formatter)
support direct input of numbers into command parameters
Provide a command that computes continuants also for general cf expansions
provide commands to change the integer-display style
work around clipping in scrolling areas
add indices to formulas of continuants
work around text wrapping of abbreviated integers
clean up todo marker