slides10.tex
changeset 87 72d0b688e942
parent 86 6a7fe83820c8
child 88 6e716ecf2db4
equal deleted inserted replaced
86:6a7fe83820c8 87:72d0b688e942
   364 Given such a program \bl{$H$} define the following program \bl{$C$}:
   364 Given such a program \bl{$H$} define the following program \bl{$C$}:
   365 for all programs \bl{$A$}\bigskip
   365 for all programs \bl{$A$}\bigskip
   366 
   366 
   367 \begin{itemize}
   367 \begin{itemize}
   368 \item \bl{$C(A) \dn 0$} iff \bl{$H(A, A) = 0$} 
   368 \item \bl{$C(A) \dn 0$} iff \bl{$H(A, A) = 0$} 
   369 \item \bl{$C(A) \dn 1$} otherwise
   369 \item \bl{$C(A) \dn$ loops} otherwise
   370 \end{itemize}
   370 \end{itemize}
   371 
   371 
   372 \end{frame}}
   372 \end{frame}}
   373 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%  
   373 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%  
   374 
   374 
   379 
   379 
   380 
   380 
   381 \bl{$H(C, C)$} is either \bl{$0$} or \bl{$1$}.
   381 \bl{$H(C, C)$} is either \bl{$0$} or \bl{$1$}.
   382 
   382 
   383 \begin{itemize}
   383 \begin{itemize}
   384 \item \bl{$H(C, C) = 1$} $\stackrel{def H}{\Rightarrow}$ \bl{$C(C)\downarrow$} $\stackrel{def C}{\Rightarrow}$ \bl{$H(C, C)=0$} 
   384 \item \bl{$H(C, C) = 1$} $\stackrel{\text{def}\,H}{\Rightarrow}$ \bl{$C(C)\downarrow$} $\stackrel{\text{def}\,C}{\Rightarrow}$ \bl{$H(C, C)=0$} 
   385 \item \bl{$H(C, C) = 0$} $\stackrel{def H}{\Rightarrow}$ \bl{$C(C)$} loops $\stackrel{def C}{\Rightarrow}$\\ 
   385 \item \bl{$H(C, C) = 0$} $\stackrel{\text{def}\,H}{\Rightarrow}$ \bl{$C(C)$} loops $\stackrel{\text{def}\,C}{\Rightarrow}$\\ 
   386 \hspace{7cm}\bl{$H(C, C)=1$} 
   386 \hspace{7cm}\bl{$H(C, C)=1$} 
   387 \end{itemize}
   387 \end{itemize}
   388 
   388 
   389 Contradiction in both cases. So \bl{$H$} cannot exist.
   389 Contradiction in both cases. So \bl{$H$} cannot exist.
   390 
   390