Large multi-line regex needed

from lark import *

grammar = r"""
expr : 
    var 
    ANY
var :
    var_atom [script]
var_atom: /[a-zA-Z]|\\alpha|\\beta|\\gamma|\\delta|\\epsilon
           |\\zeta|\\eta|\\theta|\\vartheta|\\iota
           |\\kappa|\\lambda|\\mu|\\nu|\\xi|\\pi
           |\\rho|\\varrho|\\sigma|\\tau|\\upsilon
           |\\phi|\\varphi|\\chi|\\psi|\\omega
           |\\Gamma|\\Delta|\\Theta|\\Xi|\\Pi|\\Sigma
           |\\Upsilon|\\Phi|\\Psi|\\Omega/         
script: ANY
ANY: /./+


%import common.WS
%ignore WS
"""

   
if __name__ == '__main__':
   var_parser = Lark(grammar, start='expr')
   while True:
      s = input('s=')
      tree = var_parser.parse(s)
      print(tree.pretty())

Results in NL errors.

[erezsh]

Just for the record, this should work:

var_atom: /[a-zA-Z]|\\alpha|\\beta|\\gamma|\\delta|\\epsilon/
           |/\\zeta|\\eta|\\theta|\\vartheta|\\iota/

[erezsh]

Yes, that looks alright