QED generates unlimited, exam-grade math questions and grades your work like a strict but fair examiner — step by step, criterion by criterion, in beautiful notation.
Try it free — your first 3 questions are on us. No card, no setup.
Sign in with Google or a passkey. Nothing to install, nothing to configure.
What you see below is the live product interface — not screenshots.
Show that
by giving an explicit counter-model with a domain of at most two elements. Justify why the premise holds and the conclusion fails.
A correct counter-model with a clean argument — one justification is left implicit.
Well-defined model
Domain with , is fully specified
Premise verified
Shown for ; the vacuous case deserves one sentence
Conclusion refuted
correctly breaks
Minimal two-element domain — exactly the right size
Correct use of vacuous truth for
State explicitly why the premise holds at (vacuously, since is false)
Click the math from the question to insert it, build formulas in the visual equation editor, drop in truth tables — or photograph your handwritten proof.
Stop retyping math by hand. Snap a photo of your handwritten notes or write straight onto the canvas, and QED transcribes it into clean, editable LaTeX and Markdown — fractions, integrals, matrices, summations and Greek letters included. Copy it into your assignment, thesis or lecture notes in seconds.
Most math apps stop at calculus drills. QED is built for the hard part of a university curriculum: propositional & predicate logic, where notation and rigour are everything.
Columns 3 and 4 agree on every row, hence (contraposition).
Every topic generates unlimited fresh questions at three difficulty levels — open answers graded like an exam, or rapid-fire multiple choice. Tap any topic to see how QED helps you master it.
You can — and you'll get an answer, not an education. QED is built for deliberate practice, which is how mathematics actually sticks.
A chatbot happily blesses wrong proofs. QED grades against a point rubric, verdict by verdict — "right answer, wrong reasoning" loses the reasoning points.
Every question is saved, deduplicated, rated and organised — retake it as a timed exam, export it to PDF, track mastery per topic. Chats evaporate.
Truth-table builder, visual equation editor, one-tap ∀∃∧⊨ palette — and it reads your handwritten proofs from a photo.
Ace an exam-level question and QED offers a challenge; stumble and it steps back down. Deliberate practice, not doom-prompting.
Start with 3 free questions — then pay as you go, or go Pro for the shared bank. Questions you generate are yours forever.
Yes — every new account starts with 3 free question generations, no payment details needed. Multiple-choice grading, retakes and your saved library are always free; generating a question and grading an open answer each cost 1 credit. QED Pro grades typed & LaTeX answers without limit and includes 200 handwriting grades per month.
20 university-level topics, broken into 262 subtopics. Logic and discrete mathematics: propositional and predicate logic, truth tables, natural deduction, sets, relations, equivalence relations, orderings and lattices, functions, Boolean algebra, graphs and proofs by induction. Calculus and linear algebra: limits, differentiation, integration, series, matrices, determinants, eigenvalues and differential equations. Probability and counting: conditional probability, random variables, combinatorics and number theory. Plus statistics, trigonometry, complex numbers, and foundational algebra to close prerequisite gaps.
Yes. Open the Convert tool, then either write on the canvas or upload a photo of handwritten or printed math, and QED transcribes it into clean, editable LaTeX and Markdown — you always see the rendered result to verify before you copy it. A conversion costs 1 credit, whether you use the Convert tool or the canvas inside an answer.
A chatbot gives you an answer; QED gives you an education. Every question comes with a point rubric and is graded verdict-by-verdict like a real exam — right answer with wrong reasoning loses the reasoning points. Your questions are saved, deduplicated and organised into a library you can retake as timed exams, and your mastery is tracked per topic.
Each generated question carries a hidden marking rubric. When you submit an answer — typed in real notation, built in the equation editor, or photographed from paper — the examiner scores every rubric criterion separately, awards partial credit, and shows you a full model solution.
No. Everything QED needs to generate and grade questions is included — no API keys, no third-party accounts, no separate bills. Credits are the only thing you ever pay.
Yes, cancel anytime in one click. Questions you generated yourself stay yours forever; questions you added from the community bank are part of the subscription and unlock again the moment you re-subscribe.
Generation is stochastic. Occasionally the model produces a flawed or failed generation. QED never charges a credit when generation fails — the cost of failed calls is on us, not you.
Export as you go. Questions and exam reports export beautifully to PDF — do it now and then, so your best material also lives safely on your own device.
Service availability. QED is provided as-is; no rights can be derived from temporary or permanent unavailability of the service. Credits give access to the service while it operates and confer no ownership of it.
Only what it takes to run your account. Signing in with Google stores your email address — that is how you can be reached and how your account can be recovered. Nothing else personal is kept, and your work is never shared: questions contributed to the community bank carry no link to you. You can sign in with a passkey alone and store no address at all, but then a lost passkey means a lost account.