- Decrease the default face height by one step
0 Reset the default face height to the global default
-When adjusting with `+' or `-', continue to read input events and
-further adjust the face height as long as the input event read
-\(with all modifiers removed) is `+' or `-'.
-
-When adjusting with `0', immediately finish.
+After adjusting, continue to read input events and further adjust
+the face height as long as the input event read
+\(with all modifiers removed) is one of the above characters.
Each step scales the height of the default face by the variable
`text-scale-mode-step' (a negative number of steps decreases the