(number? markup?)
font
((font-size 0)
+ (word-space 1)
(baseline-skip 2))
"Add @var{increment} to the font-size. Adjust baseline skip accordingly."
(let ((entries (list
(cons 'baseline-skip (* baseline-skip (magstep increment)))
+ (cons 'word-space (* word-space (magstep increment)))
(cons 'font-size (+ font-size increment)))))
(interpret-markup layout (cons entries props) arg)))