Proof Builder
Line-by-line LaTeX proof workspace
Scratchpad (not saved)
Save to create a persistent, shareable workspace.
Enter adds a newline. Cmd/Ctrl+Shift+Enter adds a new proof line.
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Proof Builder Help
Quick Start
1. Add a theorem title and statement at the top.
2. All inputs are plain text by default.
3. Use `$...$` for inline math and `$$...$$` or `\[...\]` for display math.
4. Proof lines can mix prose, inline math, and display equations in the same field.
5. Use `Enter` for a newline, `Cmd/Ctrl+Shift+Enter` to add and focus a proof line below, and `Tab` / `Shift+Tab` to indent or outdent.
Editing Workflow
1. Drag any line by the row handle area, or use Up/Down buttons.
2. Use Duplicate and Add Below to draft variants quickly.
3. Use the right sidebar snippets for limits, integrals, summations, and symbols.
4. Insert proof templates like Modus Ponens, contradiction, induction, and case split.
Export & Share
1. Copy output as Markdown, plain text, or LaTeX from the toolbar.
2. Use Embed to generate an embeddable version of the current proof.
3. Start a session only when you want collaborative or persisted workflow state.
Example Proofs
Modus Ponens
Logic
From P and P -> Q, conclude Q.
Theorem:
Irrationality of sqrt(2)
Number Theory
Classic contradiction proof.
Theorem:
Limit of x^2 at 2
Real Analysis
Epsilon-delta proof that lim_{x->2} x^2 = 4.
Theorem:
Kernel is a Subspace
Linear Algebra
Show ker(T) is a subspace of V.
Theorem:
Sum of First n Integers
Combinatorics
Induction proof for 1+...+n = n(n+1)/2.
Theorem:
De Morgan's Law
Set Theory
Show (A \cup B)^c = A^c \cap B^c by double inclusion.
Theorem:
Triangle Inequality in R
Metric Spaces
Derive |a+b| \le |a|+|b| from squaring.
Theorem:
Uniqueness of Identity
Abstract Algebra
If a group has identity elements e and e', then e=e'.
Theorem: