abbrevs.txt - abbreviations used in phcode.ax & utility source files
----+----|----+----|----+----|----+----|----+----|----+----|----+----|----+----8

Some abbreviations used in phonecode code & comments are given below.
(The same abbreviation may be used for different things in different contexts.)

  # - number of something (#apples), (phone) number
  > - denotes a function/map from an expression domain to a range
    domain>range
  ^(...) - push expr (...) onto stack
  fn^ - pop arg0 to use as fn parameter
  (* pred) - apply pred to tuples formed from seqs of args (can be sym prefix)
  / \ - see /binfn below 
  (. fn) - apply fn to a seq containing its input args (can be fn sym prefix)
  (& fn) - input args are included in a sequence with the fn result (sym pre)
  (: ..fn..) - apply fn compos to stack in arg0 seq giving result seq
    :fn - can be symbol prefix for 1-fn "composition"
  >=0 - zero-or-more; >0 - one-or-more
    >=n - greater-than-or-equal-to n; >n - greater-than n
  ~ - symbol prefix used for (non-Boolean) "negative" predicates (~in ~dig, ~==)
    - symbol prefix for a Boolean fn (ending in ?) that complements Bool fn
  arg - argument for a function or predicate or stack
    iarg - input argument
    oarg - output argument (result of a function)
  asn - assign expr/str to position in seq (replacing old expr/str at that pos)
  ax(s) - axiom(s), set of axioms
  bin, b, binfn, binrel, bf, br - binary (function or relation) - 2 input args
  /binfn&rel - inputs arg0 paired with arg1 seq
  \binfn&rel - inputs arg0 seq paired with arg1
    - these are generalized to preds w #args >2
  bool, Boolfn, Bf, Bf? - Boolean function (returns true/false, ? sym suffix)
  ~Bf? - complement of a Boolean function
  c - (phone number) code
  cat - [con]catenate char strings
    (see  https://www.cs.cornell.edu/courses/JavaAndDS/files/catenate.pdf ) 
    cat* - catenate a sequence of char strings into a single string
  char, ch, c - character
  chx, cx - char expr -- char or seq of char exprs
  conclu, conc - conclusion (of an axiom)
  cond - condition (of an axiom)
  consec, cnsc - consecutive (elements in a sequence)
  def, defn - define, definition of (something)
  dic - dictionary (of phonecode code words)
  dig, d - digit char
  dsym - decimal digit symbol: 3, 25
  dup - duplicate (an input arg)
  elem, el - "element" (expression) in a sequence
    (sometimes string vars in an axiom seq may be called elems of that seq)
  elim - eliminate
  expr, ex, e, x - expression
  f, `f - false (Boolean value)
  fcompos, fcomp, fc, ..fn.., ..f.. - function composition (to apply to stack) 
  filt, { - filter out (remove) seq elems which fail a Boolean predicate
     Bf?{ - application of Boolean function Bf? to filter a sequence
     *** tbd: may change filter { symbol to |
  >{ - apply map to seq, filtering out values where map is undefined
  fmt - format
  func, fn, f - function
  h-o, ho - higher-order
  id - identifier; identity function
  ins - insert (an expression/string into a sequence)
  ins_ - insert expression between elements of a sequence
  ix, idx, i - index
  lc, lcltr, lltr - lowercase (letter)
  len, l - length of a sequence
  ltr, l - letter
  num, nat, natnum - natural number
  outf, outp - output file, output
  phonenum, phnum, ph#, p# - phone number
  phcode, phc - phonecode (problem)
  pos - position of an expr/str in a seq (indexed from zero)
  pre - prefix (of a seq)
  pred - predicate (name)
  Prog - Program
  prog, progr, progg - program, programmer, programming
  rel, r - relation
  repl - replace (seq expr/str with another)
  res - result (of a function)
  rev - reverse (a sequence)
  rmv - remove (delete) an expr from a sequence
  seq - sequence
  stk - stack
  str - string of some "type" (often chars) within a seq
  suf - suffix (of a seq)
  sym - symbol
  t, `t - true (Boolean value)
  tbd - to be done, to be decided
  uc, ucltr, ultr - uppercase (letter)
  un - unary (function)
  w - with
  w/o - without