Recognize proof patterns and avoid invalid proof steps.
6 lessons · 37 questions
Recognize proof patterns and avoid invalid proof steps.
6 lessons · 37 questions
1 lessons · 8 questions
Use a **counterexample** to disprove a universal claim quickly. Use **contradiction** when assuming the opposite of a claim leads to something impossible.
1 lessons · 5 questions
In proof by contradiction, assume the target claim is false and drive the assumption to something impossible, often a parity clash or a definition failure.
1 lessons · 8 questions
When a statement has the form **if P, then Q**, you need to choose a proof path that preserves logic instead of guessing from examples.
1 lessons · 7 questions
Mathematical induction proves a statement for **every** integer in a sequence by establishing a base case and an induction step.
1 lessons · 4 questions
When a statement splits naturally into a small number of possibilities, prove each case cleanly and make sure the cases cover everything.
1 lessons · 5 questions
To prove two sets are equal, show **both inclusions** or use a membership argument with `x ∈ A` iff `x ∈ B`.