Question

I married a widow (let’s call her W) who has a grown-up daughter (call her D). My father (F), who visited us quite often, fell in love with my step-daughter and married her. Hence my father became my son-in-law and my step-daughter became my mother. Some months later, my wife gave birth to a son (S1), who became the brother-in-law of my father, as well as my uncle. The wife of my father, that is, my step-daughter, also had a son (S2).

Using predicate calculus, create a set of expressions (facts) that represent the situation in the above story. Add expressions (rules) defining basic family relationships such as the definition of father-in-law and use modus ponens on this system to prove the conclusion that “I am my own grandson.” Answer the above question.

Answer 1

Please find an attachment for diagrammatic representation of the relationship.

In diagram '+' represents the Male and '-' represents the Female.

Since we need to think on the basis of levels. Husband wife relationship is the same level.

in the above expression we come to know that his father became the Son-in-law, so we came to know that if he is her daughter's child then himself is a grandson of him.

Note:- Please let me know you want something else.