Third week

Things are more difficult in thecthird week. It requires  us to think  about more things that are related to several  sentences, for example  logical relationships and restricting domains of some expressions.
In this post, I will try to show you what I learnt on this week that can help me review those things.


On this week, the professor strats to introduce some  symbols that play an important role in natural language, The first one is conjunction(^),which combines two statements by claiming both true with logical "and". The second one is disjunction , which combines two statements by claiming that at least one of them is true like "or". The third thing is negation, which negatives the statement  like word "not". Those are main things we have to understand and use in specific cases by using other laws and methods  like De Morgan's Law  and scope. we start to translate natural sentence into symbol expression.



I also start to do the assignment with my partners . The assignment is so difficult . We have to analyze and translate specific sentences. Some sentences are to hard to understand. The most difficult thing is to translate symbol expressions into natural sentences.  It means that you have to transfer abstract symbols into specific things and then write natural sentences. Also, you have to remember some standard negation like :(P(x)^Q(x)),P(x)):Q(x). (: should be negation symbol , why it cannot be copied and paste from the professor's slides?   Ok, never mind. It is just a specific example) The logical training torments us . However,it is also interesting to learn it.