1 votes 1 votes Which of the following is true ? Mathematical Logic discrete-mathematics + – Prince Sindhiya asked Aug 15, 2018 Prince Sindhiya 561 views answer comment Share Follow See all 12 Comments See all 12 12 Comments reply arvin commented Aug 15, 2018 reply Follow Share all are true :) 0 votes 0 votes Prince Sindhiya commented Aug 15, 2018 reply Follow Share @arvin we have to read this as - if R and S are reflexive then R union S is also reflexive ? 0 votes 0 votes arvin commented Aug 15, 2018 reply Follow Share yes i have read it in that way only. all are true. 0 votes 0 votes Rishav Kumar Singh commented Aug 15, 2018 reply Follow Share Yes , all are true provided R and S are non-empty set. 0 votes 0 votes Prince Sindhiya commented Aug 15, 2018 reply Follow Share Ok i got it 0 votes 0 votes aambazinga commented Aug 15, 2018 reply Follow Share @Rishav Kumar Singh, I don't think the condition you provided as non empty set is required. 0 votes 0 votes Rishav Kumar Singh commented Aug 15, 2018 reply Follow Share aambazinga if a set is non empty then it can't be Reflexive, All though its understood but This condition should be in Question. 0 votes 0 votes aambazinga commented Aug 15, 2018 reply Follow Share You are right. But think over this, isn't it implicit that if relation R over set A is reflexive then it's non empty. And it is empty, then set A would also be empty, and then in that case too it would be reflexive. 0 votes 0 votes Rishav Kumar Singh commented Aug 15, 2018 reply Follow Share your statement "R is empty, then set A would also be empty, and then in that case too it would be reflexive", Do you think empty set is reflexive 0 votes 0 votes aambazinga commented Aug 15, 2018 reply Follow Share I might be a little unclear in expressing my statement... What I'm trying to say is.. let there is a set A which is empty. A relation R on set A would be empty too. Then I'm saying that relation R is reflexive. 0 votes 0 votes Rishav Kumar Singh commented Aug 15, 2018 reply Follow Share got you, I was unaware of this Logic https://math.stackexchange.com/questions/1203676/is-an-empty-set-reflexive-symmetric-transitive 0 votes 0 votes arvin commented Aug 15, 2018 reply Follow Share i too learned a new thing ;P cool 0 votes 0 votes Please log in or register to add a comment.