Differences
This shows you the differences between two versions of the page.
Both sides previous revision Previous revision Next revision | Previous revision Last revision Both sides next revision | ||
sav07_homework_4_solution [2007/06/16 21:40] vkuncak |
sav07_homework_4_solution [2007/06/16 21:58] vkuncak |
||
---|---|---|---|
Line 1: | Line 1: | ||
This is a sketch of the solution of [[SAV07 Homework 4]] | This is a sketch of the solution of [[SAV07 Homework 4]] | ||
+ | |||
+ | |||
Line 9: | Line 11: | ||
R(\mbox{assume}\ F}) &=& \{((x,ok),(x',ok) \mid ok\ \rightarrow\ (F(x) \land x=x' \land ok') \} | R(\mbox{assume}\ F}) &=& \{((x,ok),(x',ok) \mid ok\ \rightarrow\ (F(x) \land x=x' \land ok') \} | ||
\end{eqnarray*} | \end{eqnarray*} | ||
+ | |||
+ | Then we have | ||
+ | |||
+ | $R(assert(false))=PS^2$. | ||
+ | |||
+ | $R(assume(false))= \{ ((x,ok),(x',ok')) | \lnot ok \}$ | ||
+ | |||
+ | Then we have $R(assert(false)) \circ R(assume(false)) = PS^2 = R(assert(false))$. | ||
+ | |||
+ | Note that we have $R(assume(false)) \circ R(assert(false)) = R(assume(false))$. | ||
+ | |||
+ | Basically, $R(assert(false))$ and $R(assume(false))$ both act as a left zeros of $\circ$ for the relations of the form $R(c)$. | ||
==== Part 2 ==== | ==== Part 2 ==== |