define(`transponiert',`c')

define(`forloop',
       `pushdef(`$1', `$2')_forloop(`$1', `$2', `$3', `$4')popdef(`$1')')
define(`_forloop',
       `$4`'ifelse($1, `$3', ,
		   `define(`$1', incr($1))_forloop(`$1', `$2', `$3', `$4')')')

define(`strophen_varianten',
       `undefine(`_strophen_varianten_andere')'
       `undefine(`_strophen_varianten_diese')'
       `forloop(str,1,20,
          `ifdef(`STR_'str,
                 `ifelse(
                   index(` $1 ',` 'str` '),`-1',
                   `define(_strophen_varianten_andere,str)',
                   `define(_strophen_varianten_diese,str)'
                   )'
                 )'
       )'
       `ifdef(`_strophen_varianten_diese',`ifdef(`_strophen_varianten_andere',```$3''',```$2''')',$4)'
)