1. Frbs version 1.0-0
    1. The first version.
    2. There are 9 learning methods: WM, GFS, HyFIS, ANFIS, frcs, DENFIS, SBC, DM, HGD, MSGFS.
  2. Frbs version 2.0-0:
    1. Delete a learning method: GFS.
    2. Change the name of learning methods: MSGFS, frcs, DM, and HGD .
    3. Add new learning methods: FRBCS.CHI, GFS.GCCL, FH.GBML, SLAVE, GFS.THRIFT.
    4. Export functions: inference, rulebase, defuzzier, fuzzifier.
    5. Improve description of summary by refine summary() function.
    6. Improve plotting by refine plotMF() function.
    7. Add examples and demo.
  3. Frbs version 2.1-0:
    1. Refine and make standard FRBS object.
    2. Add a learning method: GFS.LT.RS.
    3. Refine description of summary.
    4. Optimize some code.
    5. Improve functionality of frbs.gen() as a interface function of manual FRBS.
    6. Provide new examples and demo.
  4. Frbs version 2.2-0:
    1. Provide fixed linguistic values for corresponding the number of labels: 3, 5, 7. 
    2. Reduce the computation time by vectorizing code.
    3. Provide the text progress bar.
    4. Refine the package manual.