 DP_Nat:    * kernel/DP communication:         s/mult/time/g for symbols names in DP procedure    * naive polynoms library was dead bugged:      - oflist: zip sequences of monoms:          [(x, 1); (x, -1)] -(zip)-> [(x, 0)] -(filter)-> []      - multiplication: rewritten
 DP_Nat:
   * kernel/DP communication:
        s/mult/time/g for symbols names in DP procedure
   * naive polynoms library was dead bugged:
     - oflist: zip sequences of monoms:
         [(x, 1); (x, -1)] -(zip)-> [(x, 0)] -(filter)-> []
     - multiplication: rewritten

strub/coqmt,strub/coqmt,strub/coqmt