A counter-example.
It's called a proof
The Poincaré Conjecture.
a proof
It is a proof.
A counter-example.
It's called a proof
The Poincaré Conjecture.
a proof
a proof
It is a proof.
Counterexample
it is called a conjecture
a conjecture is disproved if it is shown to be false. this can be done by providing a single concrete example (e.g. with actual numbers, functions, etc) that shows the conjecture's premise does not necessarily lead to its conclusion. alternatively, a conjecture could be shown to be false (i.e. disproved) by demonstrating that IF it were true then a logical consequence would be a clearly wrong statement (e.g. 2 + 2 =5)
a conjecture
To be true a Conjecture must be true for all cases.
Because that is what a conjecture is! It is a proposition that has to be checked out to see f it isalways true, false or indeterminate,sometimes true, false or indeterminate,never true, false or indeterminate.Once its nature has been decided then it is no longer a conjecture.