anchor.diff:  "ZTEST", "Z.TEST"]	    
   
       let Arity3FunctionName: P<string> = ArityNFunctionNameMaker 3 ["CHOOSE", "DATE", "FIND", "FINDB", "IF", "INDEX", "LOOKUP", "MATCH", 
  +"PDURATION", "PERCENTRANK.EXC", "PERCENTRANK.INC", "PERCENTRANK", "PMT", "POISSON.DIST", "POISSON", "PROB", "PRODUCT", "PV", 
   "RANK.AVG", "RANK.EQ", "RANK", "RATE", "REGISTER.ID", "RRI", "RTD", 
   "SEARCH", "SEARCHB", "SKEW", "SKEW.P", "SLN", "SQL.REQUEST", "STANDARDIZE", "STDEV", "STDEV.P", "STDEV.S", "STDEVA", "STDEVP", "STDEVPA", "SUBSTITUTE", "SUBTOTAL", "SUM", "SUMIF", "SUMIFS", "SUMPRODUCT", "SUMSQ", "SWITCH",
   "TBILLEQ", "TBILLPRICE", "T.DIST", "TDIST", "T.DIST.2T", "TEXTJOIN", "TIME", "TREND",
  
positive.code: "YEAR"]
  
      let Arity2FunctionName: P<string> = ArityNFunctionNameMaker 2 ["CHOOSE", "DAYS", "FIND", "FINDB", "INDEX", "LOOKUP", "MATCH", 
  "RANDBETWEEN", "RANK.AVG", "RANK.EQ", "RANK", "REGISTER.ID", "REPT", "RIGHT", "RIGHTB", "ROMAN", "ROUND", "ROUNDDOWN", "ROUNDUP", "RSQ",
  "SEARCH", "SEARCHB", "SKEW", "SKEW.P", "SLOPE", "SMALL", "SQL.REQUEST", "STDEV", "STDEV.P", "STDEV.S", "STDEVA", "STDEVP", "STDEVPA", "STEYX", "SUBTOTAL", "SUM", "SUMIF", "SUMPRODUCT", "SUMSQ", "SUMX2MY2", "SUMX2PY2", "SUMXMY2", 
  "TBILLYIELD", "T.DIST.RT", "TEXT", "T.INV", "TINV", "T.INV.2T", "TREND", "TRIMMEAN", "TRUNC",
  
negative.code: 
      let ArityNFunctionNameMaker n xs = xs |> List.map (fun name -> attempt (pstring name)) |> choice <!> ("Arity" + n.ToString() + "FunctionName")
  
      let Arity0FunctionName: P<string> = ArityFunctionNameMaker 0 ["PI", "RAND", "ROW", "SHEET", "SHEETS", "TODAY", "TRUE"]
  
      let Arity1FunctionName: P<string> = ArityNFunctionNameMaker 1 ["ABS", 
  "PHI", "PHONETIC", "PRODUCT", "PROPER",
  "RADIANS", "RIGHT", "RIGHTB", "ROMAN", "ROW", "ROWS",
  "SEC", "SECH", "SECOND", "SHEET", "SHEETS", "SIGN", "SIN", "SINH", "SKEW", "SKEW.P", "SQL.REQUEST", "SQRT", "SQRTPI", "STDEV", "STDEV.P", "STDEV.S", "STDEVA", "STDEVP", "STDEVPA", "SUM", "SUMPRODUCT", "SUMSQ", 
  "T", "TAN", "TANH", "TIMEVALUE", "TRANSPOSE", "TREND", "TRIM", "TRUNC", "TYPE",
  