| return_value = NumRu::DCL.isgtrc(ctr) | A function that returns the  
  transformation function number when a name or abbreviation is given. | 
 
| ltr = NumRu::DCL.sgtrqf(ntx) | Checks whether a transformation   
  function number (NTX) is defined. When defined, it returns the value  .true.   
  for   ltr, when not defined, .false.. | 
 
| ctl = NumRu::DCL.sgtrsl(cts) | Returns the name when given the abbreviation. | 
 
| ntx = NumRu::DCL.sgtrsn(cts) | Returns the transformation function number when  
  given the abbreviation. | 
 
| cts = NumRu::DCL.sgtrls(ctl) | Returns the abbreviation when given the name. | 
 
| ntx = NumRu::DCL.sgtrln(ctl) | Returns the transformation function number when  
  given the name. | 
 
| cts = NumRu::DCL.sgtrns(ntx) | Returns the abbreviation when given the  
  transformation function number. | 
 
| ctl = NumRu::DCL.sgtrnl(ntx) | Returns the name when given the  
  transformation function number. |