Implicit Subclass Rule

Let

	B = C#(S1; S2; ... ; Sn)P1,...,Pg 
	A = C#(T1; T2; ... ; Tm)Q1,...,Qh

• for each class parameter Si defined in B, there is a Tj in A, such that
  • if Si is a type name in the form Si=X, Tj is in the form Tj=Y, and X is equivalent to Y;
  • if Si is a type name in the form Si:X, Tj is in the form Tj=Y, and Y is subtype of X;
  • if Si is an object name in the form Si=X, Tj is in the form Tj=Y, and X and Y are constants with equal value;
• for each interface with list type Pi defined in B, there is an interface with list type Qj in A, such that Pi is equivalent to Qj.

If A is an implicit subclass of B and B is an implicit subclass of A, A and B are equivalent simple classes.

Tuple Subtype Rule

Given two tuple types:

    L1 =   < S1:C1; S2:C2; ... ; Sn:Cn > (e1:E1; e2:E2; ... ; ep:Ep)
    L2 =   < T1; T2; ... ; Tm > (f1:F1; f2:F2; ... ; fq:Fq)

• m>=n and q>=p; and
• for each Si in L1, Ti in L2 has the form either Si:Di or Si=Di where Di is subtype of Ci;
• for each element ei:
  • if it is a type name Ei is a subtype of Fi;
  • otherwise Ei is equivalent to Fi;