If ‘A $ B’ means ‘A is father of B’, 

‘A # B’ means ‘A is daughter of B’, 

‘A @ B’ means ‘A is sister of B’,

then how is K related to M in the following equation ?

     H @ K $ L # M ?

Husband

Note:

↑ or ↓ ⇒ Upward or downward line shown "generation gap" .

   =    ⇒ Double lines shown "relation b/w Husband & Wife"

   —   ⇒ single line shown "relation between them other than Husband & Wife".

   +   ⇒ Plus sign shown " Male".

   -   ⇒minus sign shown " Female".