if r1 and r2 are two relations or functions then

Question

If R1 and R2 are two relations or functions, then the result of R3 = R1 × R2 is the combination of tuples that are in R1 and R2. The product is associative and commutative.

Degree (R3) =Degree of (R1) + Degree (R2).

In case, R3 will have tuples such that R3 = {t1 || t2 | R1 ∋ t1  ∧ R2 ∋ t2}.

Example:

R2

A B A1 B1 A2 B2 A3 B3 A4 B4

       R1                         

C C1 C2

       

R3 = R1 × R2 is

 

A	B	C
A1	B1	C1
A1	B1	C2
A2	B2	C1
A2	B2	C2
A3	B3	C1
A3	B3	C2
A4	B4	C1
A4	B4	C2