What do they mean?

The Symbolics Zetalisp character set includes the following
characters not present in other Lisps (^ means control):
   ^]      >=      greater than or equal to
   ^\      <=      less than or equal to
   ^Z      !=      not equal to
   ^^      ==      equivalent to 
   ^E      not
   ^G      pi
   ^L      +/-     plus/minus
   ^H      lambda
   ^F      epsilon
   ^W      <-->    left/right arrow
   ^X      <--     left arrow
   ^Y      -->     right arrow
   ^A              down arrow
   ^K              up arrow
   ^D              up caret
   ^_              down caret
   ^T              forall
   ^U              there exists
   ^B              alpha
   ^C              beta
   ^I              gamma
   ^J              delta
   ^O              partial delta  
   ^N              infinity
   ^M              circle +
   ^V              circle x

Other special characters to look out for are the font-change characters,
which are represented as a ^F followed by a digit or asterisk. A digit
means to push font #N onto the stack; an asterisk means to pop the most
recent font from the stack. You can clean up the code by replacing "\^F."
with "". In format statements, ^P and ^Q are used to delimit text to
be printed in a particular character style.