Chapter 2.4, Problem 60PS

To determine

a) To insert:

$“=”$ or $“\ne ”$ in given box ${\aleph }_0\square {\aleph }_0+{\aleph }_0$.

To determine

b) To insert:

$“=”$ or $“\ne ”$ in given box $2{\aleph }_0\square {\aleph }_0+{\aleph }_0+{\aleph }_0$.

To determine

c) To insert:

$“=”$ or $“\ne ”$ in given box ${\aleph }_0+2\square {\aleph }_0-2$.

To determine

d) To insert:

$“=”$ or $“\ne ”$ in given box $\left|\mathbb{N}\right|\square {\aleph }_0$.