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Fast Algorithm for 2 Parallel Rules


  Assume the inference of two parallel rules represented in a schematic form as:

Rule 1 : IF X is tex2html_wrap_inline1520 THEN Y is tex2html_wrap_inline1600
Rule 2 : IF X is tex2html_wrap_inline1700 THEN Y is tex2html_wrap_inline1704
Fact : X is tex2html_wrap_inline1358
Conclusion : Y is tex2html_wrap_inline1366

The basic idea of this algorithm consists in generating

The parameterized computation is based on the inclusion of tex2html_wrap_inline1730 in tex2html_wrap_inline1732 and/or in tex2html_wrap_inline1734 characterized by two parameters tex2html_wrap_inline1736 and tex2html_wrap_inline1738 . This algorithm uses the simple generalized modus ponens tex2html_wrap_inline1740 for four major cases characterized by four possible binary values of tex2html_wrap_inline1736 and tex2html_wrap_inline1738 :

However tex2html_wrap_inline1730 does not always respect the previous properties, so tex2html_wrap_inline1736 and tex2html_wrap_inline1738 are not always binary values and we have defined four new major cases:

The fast parallel generalized modus ponens algorithm called tex2html_wrap_inline1792 is defined by tex2html_wrap_inline1794 and his body is:

 Begin

    ¯ tex2html_wrap_inline1796

    tex2html_wrap_inline1798

    tex2html_wrap_inline1800

    tex2html_wrap_inline1802

    tex2html_wrap_inline1804

    tex2html_wrap_inline1806

    tex2html_wrap_inline1808

    tex2html_wrap_inline1810 \ tex2html_wrap_inline1812

    If tex2html_wrap_inline1814 and tex2html_wrap_inline1816 Then

      ¯ tex2html_wrap_inline1818

    If ( tex2html_wrap_inline1820 ) Then

      ¯ tex2html_wrap_inline1822

      tex2html_wrap_inline1824

    If ( tex2html_wrap_inline1826 ) Then

      tex2html_wrap_inline1828

      tex2html_wrap_inline1830

    Else if tex2html_wrap_inline1832 and tex2html_wrap_inline1834 Then

        tex2html_wrap_inline1836

      If ( tex2html_wrap_inline1838 ) Then

        tex2html_wrap_inline1840

        tex2html_wrap_inline1842

      If ( tex2html_wrap_inline1844 ) Then

        tex2html_wrap_inline1846

      tex2html_wrap_inline1848

      Else if tex2html_wrap_inline1850 and tex2html_wrap_inline1852 Then

          tex2html_wrap_inline1366 =min( ¯ tex2html_wrap_inline1858

          tex2html_wrap_inline1860

      If ( tex2html_wrap_inline1838 ) Then

        tex2html_wrap_inline1864

        tex2html_wrap_inline1866

      If ( tex2html_wrap_inline1826 ) Then

        tex2html_wrap_inline1870

        tex2html_wrap_inline1872

      Else if tex2html_wrap_inline1874 and tex2html_wrap_inline1876 Then

        tex2html_wrap_inline1366 =max( ¯ tex2html_wrap_inline1882

        tex2html_wrap_inline1884

      If ( tex2html_wrap_inline1820 ) Then

        tex2html_wrap_inline1822

        tex2html_wrap_inline1890

      If ( tex2html_wrap_inline1844 ) Then

        tex2html_wrap_inline1894

        tex2html_wrap_inline1848

End

The principle of this fast parallel algorithm is to select a case with respect to tex2html_wrap_inline1736 and tex2html_wrap_inline1738 and compute tex2html_wrap_inline1366 with tex2html_wrap_inline1740 as if tex2html_wrap_inline1736 and tex2html_wrap_inline1738 are binary values.

If tex2html_wrap_inline1736 and tex2html_wrap_inline1738 are not binary value, the algorithm modifies the core and the support of tex2html_wrap_inline1366 with respect to tex2html_wrap_inline1916 and tex2html_wrap_inline1918 which characterize the inclusion of tex2html_wrap_inline1920 in tex2html_wrap_inline1922 and/or in tex2html_wrap_inline1924 . A parameter tex2html_wrap_inline1926 is equally introduced to compute the final uncertainty of tex2html_wrap_inline1366 .


Figure 7: Core computation for 2 parallel rules.

   figure568


In case (a), tex2html_wrap_inline1366 is computed only from tex2html_wrap_inline1600 parameters, and there is a possible displacement of tex2html_wrap_inline1366 if tex2html_wrap_inline1826 and tex2html_wrap_inline1820 . This displacement is obtained by projecting onto V, the intersection of the core of tex2html_wrap_inline1358 and the core of tex2html_wrap_inline1944 to find the core of tex2html_wrap_inline1366 as shown in the figure 7. The core of tex2html_wrap_inline1944 is represented in grey.

Moreover supports are approximated to eliminate scale effect in tex2html_wrap_inline1366 as shown in figure 8. Supports are cut from the core along the support to eliminate the part of the support under tex2html_wrap_inline1462 if tex2html_wrap_inline1954 . Equally supports are averaged to take into account the part of the support under tex2html_wrap_inline1462 if tex2html_wrap_inline1958 .

This solution is applied for all the cases (a), (b), (c), (d) and tries to respect the shape of tex2html_wrap_inline1366 as possible.



Figure 8: Support approximation.

   figure579

The case (b) is a similar to case (a).

The case (c) modify cores and supports with an extension if tex2html_wrap_inline1962 .

The case (d) modifies cores and supports as does case (c), with a reduction if tex2html_wrap_inline1964 .

But if tex2html_wrap_inline1966, the fuzzy set tex2html_wrap_inline1366 cannot be evaluated by tex2html_wrap_inline1970 ( tex2html_wrap_inline1972 ) because the extension of the core is not equal for each side of tex2html_wrap_inline1520 and tex2html_wrap_inline1700 . So we have introduced two parameters tex2html_wrap_inline1978 and tex2html_wrap_inline1980 to take into account this particularity.



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