You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

20 lines
889 B

  1. \setlength\subproofhorizspace{1.3em}
  2. \begin{logicproof}{2}
  3. \exists x \;(P(x) \lor Q(x)) & prem.\\
  4. \begin{subproof}
  5. \llap{$x_0\enspace \;$} P(x_0) \lor Q(x_0) & ass.\\
  6. \begin{subproof}
  7. P(x_0) & ass.\\
  8. \exists x \; P(x) &$ \exists\mathrm{i} 3$\\
  9. \exists x \; P(x) \lor \exists x \; Q(x) &$ \lor\mathrm{i} 4$
  10. \end{subproof}
  11. \begin{subproof}
  12. Q(x_0) & ass.\\
  13. \exists x \; Q(x) &$ \exists\mathrm{i} 6$\\
  14. \exists x \; P(x) \lor \exists x \; Q(x) &$ \lor\mathrm{i} 7$
  15. \end{subproof}
  16. \exists x \;P(x) \lor \exists x \; Q(x) &$ \lor\mathrm{e} 2,3-8$
  17. \end{subproof}
  18. \exists x \;P(x) \lor \exists x \; Q(x) & $\exists\mathrm{e} 1,2-9$
  19. \end{logicproof}