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Diffstat (limited to 'usr.bin/learn/lib/eqn/L11.1f')
| -rw-r--r-- | usr.bin/learn/lib/eqn/L11.1f | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/usr.bin/learn/lib/eqn/L11.1f b/usr.bin/learn/lib/eqn/L11.1f new file mode 100644 index 00000000000..0a726f4babf --- /dev/null +++ b/usr.bin/learn/lib/eqn/L11.1f @@ -0,0 +1,48 @@ +#once #create message +.ND +.tr %$ +.EQ +delim $$ +.EN +.LP +The way to handle the problem of a subscript or superscript +on nothing is to provide something to hang the subscript +or superscript on. +One possibility is to use a tilde, but that has a real width, +and might spoil the appearance of the output. +The best solution is this: + + "" sup 1 ... + +The expression "" has no width, so everything works +out properly. The use of "" may seem a bit unnatural +but it's an idiom that you get used to quite quickly. + +For practice, modify "Example" so it produces +output that looks like this, +then type "ready". +.pl 1 +#once #create Ref +.LP +.EQ +"" sup + H sub 2 ~ "<=>" ~ "" sup - H ~+~ "" sup + H +.EN +.pl 1 +#once #create Example +.LP +.EQ +xxx +.EN +.pl 1 +# +#once neqn Ref | nroff >X1 & +#once neqn message Ref | nroff -T$term %s/tinyms - +#user +neqn Example | nroff >X2 +#cmp X1 X2 +#fail +Don't forget spaces; don't forget to quote +things when needed (including <=>). +#log +#next +11.1g 10 |