Exercises on reductions of programs

  1. K    {py:  Mp(y)}K\;\leq\;\{ p \mid \exists y:\;M_p(y){\downarrow} \}
  2. K    {py:  Mp(y)}\overline{K}\;\leq\;\{ p \mid \forall y:\;M_p(y){\downarrow} \}
  3. K    {py:  Mp(y)}\overline{K}\;\leq\;\{ p \mid \exists y:\;M_p(y){\uparrow} \}
  4. K    {py:  Mp(y)}\overline{K}\;\leq\;\{ p \mid \forall y:\;M_p(y){\uparrow} \}
  5. K    {py:  Mp(y)=y}\overline{K}\;\leq\;\{ p \mid \forall y:\;M_p(y)=y \}
  6. K    {pφp total and injective}\overline{K}\;\leq\;\{ p \mid \varphi_p\text{ total and injective} \}
  7. K    {pφp total and non-injective}\overline{K}\;\leq\;\{ p \mid \varphi_p\text{ total and non-injective} \}
  8. K    {pMp(1)Mp(2)}\overline{K}\;\leq\;\{ p \mid M_p(1){\downarrow} \,\wedge\, M_p(2){\uparrow} \}
  9. K    {pDom(φp)2}K\;\leq\;\{ p \mid |\mathtt{Dom}(\varphi_p)|\geq 2 \}
  10. K    {pDom(φp)=2}\overline{K}\;\leq\;\{ p \mid |\mathtt{Dom}(\varphi_p)|=2 \}
  11. K    {pIm(φp)2}K\;\leq\;\{ p \mid |\mathtt{Im}(\varphi_p)|\geq 2 \}
  12. K    {pIm(φp)=2}\overline{K}\;\leq\;\{ p \mid |\mathtt{Im}(\varphi_p)|=2 \}
  13. K    {pDom(φp)=    Im(φp)=    Dom(φp)Im(φp)=}\overline{K}\;\leq\;\{ p \mid |\mathtt{Dom}(\varphi_p)|=\infty\;\wedge\;|\mathtt{Im}(\varphi_p)|=\infty\;\wedge\;\mathtt{Dom}(\varphi_p)\cap\mathtt{Im}(\varphi_p)=\emptyset \}
  14. K    {p,qy:  (Mp(y)Mq(y))}K\;\leq\;\{ \langle p,q\rangle \mid \exists y:\;(M_p(y){\downarrow} \,\wedge\, M_q(y){\downarrow}) \}
  15. K    {p,qy:  (Mp(y)Mq(y))}\overline{K}\;\leq\;\{ \langle p,q\rangle \mid \exists y:\;(M_p(y){\downarrow} \,\wedge\, M_q(y){\uparrow}) \}
  16. K    {p,qy1,y2:  (Mp(y1)Mq(y1)Mp(y2)Mq(y2))}\overline{K}\;\leq\;\{ \langle p,q\rangle \mid \exists y_1,y_2:\;(M_p(y_1){\downarrow} \,\wedge\, M_q(y_1){\uparrow} \,\wedge\, M_p(y_2){\uparrow} \,\wedge\, M_q(y_2){\downarrow}) \}
  17. K    {p,qDom(φp)Dom(φq)2}K\;\leq\;\{ \langle p,q\rangle \mid |\mathtt{Dom}(\varphi_p)\cap\mathtt{Dom}(\varphi_q)|\geq 2 \}
  18. K    {p,qDom(φp)Dom(φq)=2}\overline{K}\;\leq\;\{ \langle p,q\rangle \mid |\mathtt{Dom}(\varphi_p)\cap\mathtt{Dom}(\varphi_q)|=2 \}
  19. K    {p,qDom(φp)=Dom(φq)=Im(φp)=Im(φq)=1    Dom(φp)Dom(φq)Im(φp)Im(φq)=1}\overline{K}\;\leq\;\{ \langle p,q\rangle \mid |\mathtt{Dom}(\varphi_p)|=|\mathtt{Dom}(\varphi_q)|=|\mathtt{Im}(\varphi_p)|=|\mathtt{Im}(\varphi_q)|=1\;\wedge\;|\mathtt{Dom}(\varphi_p)\cup\mathtt{Dom}(\varphi_q)\cup\mathtt{Im}(\varphi_p)\cup\mathtt{Im}(\varphi_q)|=1 \}
  20. K    {p,qDom(φp)=Dom(φq)=Im(φp)=Im(φq)=1    Dom(φp)Dom(φq)Im(φp)Im(φq)=2}\overline{K}\;\leq\;\{ \langle p,q\rangle \mid |\mathtt{Dom}(\varphi_p)|=|\mathtt{Dom}(\varphi_q)|=|\mathtt{Im}(\varphi_p)|=|\mathtt{Im}(\varphi_q)|=1\;\wedge\;|\mathtt{Dom}(\varphi_p)\cup\mathtt{Dom}(\varphi_q)\cup\mathtt{Im}(\varphi_p)\cup\mathtt{Im}(\varphi_q)|=2 \}
  21. K    {p,qDom(φp)=Dom(φq)=Im(φp)=Im(φq)=1    Dom(φp)Dom(φq)Im(φp)Im(φq)=3}\overline{K}\;\leq\;\{ \langle p,q\rangle \mid |\mathtt{Dom}(\varphi_p)|=|\mathtt{Dom}(\varphi_q)|=|\mathtt{Im}(\varphi_p)|=|\mathtt{Im}(\varphi_q)|=1\;\wedge\;|\mathtt{Dom}(\varphi_p)\cup\mathtt{Dom}(\varphi_q)\cup\mathtt{Im}(\varphi_p)\cup\mathtt{Im}(\varphi_q)|=3 \}
  22. K    {p,qDom(φp)=Dom(φq)=Im(φp)=Im(φq)=1    Dom(φp)Dom(φq)Im(φp)Im(φq)=4}\overline{K}\;\leq\;\{ \langle p,q\rangle \mid |\mathtt{Dom}(\varphi_p)|=|\mathtt{Dom}(\varphi_q)|=|\mathtt{Im}(\varphi_p)|=|\mathtt{Im}(\varphi_q)|=1\;\wedge\;|\mathtt{Dom}(\varphi_p)\cup\mathtt{Dom}(\varphi_q)\cup\mathtt{Im}(\varphi_p)\cup\mathtt{Im}(\varphi_q)|=4 \}
  23. K    {p,qDom(φp)Dom(φq)}\overline{K}\;\leq\;\{ \langle p,q\rangle \mid \mathtt{Dom}(\varphi_p)\subseteq\mathtt{Dom}(\varphi_q) \}
  24. K    {p,qDom(φp)Dom(φq)}\overline{K}\;\leq\;\{ \langle p,q\rangle \mid \mathtt{Dom}(\varphi_p)\subset\mathtt{Dom}(\varphi_q) \}
  25. K    {p,qDom(φp)Dom(φq)Im(φp)}\overline{K}\;\leq\;\{ \langle p,q\rangle \mid \mathtt{Dom}(\varphi_p)\subset\mathtt{Dom}(\varphi_q)\subset\mathtt{Im}(\varphi_p) \}
  26. K    {p,qDom(φp)=    Dom(φq)=    Dom(φp)Dom(φq)=}\overline{K}\;\leq\;\{ \langle p,q\rangle \mid |\mathtt{Dom}(\varphi_p)|=\infty\;\wedge\;|\mathtt{Dom}(\varphi_q)|=\infty\;\wedge\;\mathtt{Dom}(\varphi_p)\cap\mathtt{Dom}(\varphi_q)=\emptyset \}
  27. K    {p,qDom(φp)=    Dom(φq)=    Dom(φp)Dom(φq)=    y:Dom(φp){0,,y}>Dom(φq){0,,y}}\overline{K}\;\leq\;\{ \langle p,q\rangle \mid |\mathtt{Dom}(\varphi_p)|=\infty\;\wedge\;|\mathtt{Dom}(\varphi_q)|=\infty\;\wedge\;\mathtt{Dom}(\varphi_p)\cap\mathtt{Dom}(\varphi_q)=\emptyset\;\wedge\;\forall y:|\mathtt{Dom}(\varphi_p)\cap\{0,\ldots,y\}|>|\mathtt{Dom}(\varphi_q)\cap\{0,\ldots,y\}| \}