0 votes 0 votes How to write the last line of Qno. 19 - irrespective of whether the system has been armed the alarm should go off when there is fire For Qno 20 I am getting iii) and iv) as true but answer is a) please check the 5th one Mathematical Logic zeal mathematical-logic first-order-logic zeal-workbook + – Prince Sindhiya asked Nov 9, 2018 • edited Mar 9, 2019 by ajaysoni1924 Prince Sindhiya 855 views answer comment Share Follow See all 7 Comments See all 7 7 Comments reply Mk Utkarsh commented Nov 9, 2018 reply Follow Share iv is true because $\exists y$ which is 0 x+0 = x - 0 1 votes 1 votes Prince Sindhiya commented Nov 9, 2018 reply Follow Share @utkarsh , actually I am getting 3) and 4) but not 5) I will edit it ∃y which is 0 x+0 = x - 0 But in 5) how we can have some y for every x(here y need not be same ) 0 votes 0 votes Mk Utkarsh commented Nov 9, 2018 reply Follow Share for all y there exist x $(\forall y \exists x)$ yes this is true that x is 0 0 votes 0 votes Prince Sindhiya commented Nov 9, 2018 reply Follow Share @utkarsh how both 4 and 5) can be equal 0 votes 0 votes Mk Utkarsh commented Nov 9, 2018 reply Follow Share they are not, in 4 y = 0 satisfies the equation but in 5 x = 0 satisfies the equation 0 votes 0 votes Prince Sindhiya commented Nov 9, 2018 reply Follow Share @utkarsh please see the question again you are telling about 6) the one 0 votes 0 votes Mk Utkarsh commented Nov 9, 2018 reply Follow Share i'm sorry i got confused i'll solve it in sometime 0 votes 0 votes Please log in or register to add a comment.
0 votes 0 votes In 20th, 5th is true. The statement says "For all x, there exists a y such that x + y = x - y." This is true because we can take x to be any value and for any such value, y = 0 will always satisfy the proposition Q(x,y). goxul answered Nov 9, 2018 goxul comment Share Follow See 1 comment See all 1 1 comment reply Prince Sindhiya commented Nov 11, 2018 reply Follow Share @goxul FOr every x there exist a y (y need not be same) there exist a y FOr every x (y is same for all x i.e is 0) so both are different 0 votes 0 votes Please log in or register to add a comment.