one or more statements that amount to a contradiction

another word for antimony

a couple of quackers flying over TWU

equivalent to having P → ~P

two PhDs sharing an office

another word for alimony

three twos

two threes

3 + 3

two groups of three

2 + 2 + 2

three groups of two

it wasn't a Moore machine or a TM

it looped forever

it is self-referential

it always halted before it could do anything

attempting to depict/construct one produced a contradiction

always halts with a Boolean-style output that determines whether I ∈ N_π or not

loops or halts depending on whether the output is True or not

can be represented with a Moore machine

is TC

ends in a non-accepting state if the problem is unsolvable

that addition and multiplication are TC

that the reals are uncountable

that any subset of  the natural numbers is countable

that the rationals are countable 

that the sum of all natural numbers is countable