An Expert System Devoted to Automated Music Identification and Recognition - Intelligent Music Information Systems: Tools and Methodologies - page 88

Table 2 gives rise to eight production rules.
For instance, row X1∧X2 and column ¬X3, give
rise to the production rule:

Table 3. Another first level table

X21 ¬X21

X19 ^ X20 H3 H3

¬X19 ^ X20 H2 H2

X1 ∧ X2 ∧ ¬X3 → A3

X19 ^ ¬X20 H1 H3

¬X19 ^ ¬X20 H2 H2

(“Rule 32” in ES1), which means:

“IF religious = yes AND solemn = yes AND
sumptuous = no

C3 and C4, which represent the Baroque,
Rococo, Classic and “none of these condi-
tions ”, respectively.

THEN Classic tendency_I”.

• The combinations of X9 to X11 and their

contraries give rise to the literals D1, D2
and D3 which represent the Baroque style_ I,
Rococo style_ I, and Classic style_ I. D4
means “none of these styles_I”.

Another example is “Rule 5” of ES1:

X1 ∧ ¬X2 ∧ X3 → A1

which means:

• The combinations of X12, X13 and their

contraries give rise to the literals E1, E2, and
E3, which represent the Baroque tendency II,
Rococo tendency II and Classic tendency II.

“IF religious = yes AND solemn = no AND
sumptuous = yes

THEN Baroque tendency_I”.

• The combinations of X14 to X16 and their

contraries give rise to the literals F1, F2, F3
and F4, which represent the Baroque style_ II,
Rococo style_ II, Classic style_ II and “none
of these styles_II”.

As a matter of fact, the eight rules obtained
from Table 2 can be rearranged, using logic-based
simplifications, into only three:

• The combinations of X17, X18 and their

contraries give rise to the literals G1, G2, and
G3, which represent the Baroque, Rococo
and Classic qualities , respectively.

X1 ∧ X3 → A1
¬X1 ∧ X3 → A2
¬X3 → A3

• The combinations of X19 to X21 and their

contraries give rise to the literals H1, H2 and
H3 which represent the Baroque, Rococo, and
Classic structure, respectively (see Table 3).

The remaining potential facts and their con-
traries are arranged in similar first level tables.
It needs to be emphasized that these diagrams
are not built arbitrarily, but always following the
experts' opinions. Each first level table gives rise
to a set of production rules.

Table 3 gives rise to eight production rules,
which are rearranged into the next five ones:

• The combinations of X4, X5 and their con-

traries give rise to the literals B1, B2, and
B3, which represent the Baroque, Rococo
and Classic characteristics , respectively.

X19 ^ X20 → H3
¬X19 ^ X20 → H2
X19 ^ ¬X20 ^ X21 → H1
X19 ^ ¬X20 ^ ¬X21 → H3
¬X19 ^ ¬X20 → H2

• The combinations of X6 to X8 and their

contraries give rise to the literals C1, C2,