Fitch Logic Proof Calculator for Construction

Check natural deduction steps for construction disputes. Validate rules, line references, scopes, and conclusions quickly. Download proof records for teams and field reviewers today.

Calculator Inputs

Line format:

line ; depth ; formula ; rule ; refs

Use ranges like 3-6. Accepted operators are ~, &, |, ->, <->, and BOT.

Formula Used

The calculator checks Fitch natural deduction patterns. Important formulas include these rule forms:

How To Use This Calculator

  1. Enter project and reviewer details.
  2. Enter each premise on its own line.
  3. Enter the target conclusion.
  4. Write each proof step with line number, depth, formula, rule, and references.
  5. Use depth zero for main proof lines. Increase depth inside assumptions.
  6. Submit the form. The result appears above the form.
  7. Use CSV or PDF buttons to save the current review.

Example Data Table

Line Depth Formula Rule Refs Construction meaning
1 0 PermitApproved -> AccessAllowed Premise If the permit is approved, access is allowed.
2 0 PermitApproved Premise The permit is approved.
3 0 AccessAllowed ->E 1,2 Access follows from the rule and fact.

Fitch Proofs for Construction Logic

A construction decision often depends on clear conditions. A permit may require a survey. A concrete pour may require inspection. A lift plan may require certified equipment. Fitch logic helps teams write these conditions as exact statements. Each line is checked by a rule. Each cited line must be available. Each temporary assumption must stay inside its proper scope.

Why This Calculator Helps

This calculator gives a structured proof review. It accepts premises, a target conclusion, and proof lines. The checker studies formula shape, rule names, cited references, and subproof ranges. It also reports missing premises, invalid citations, depth jumps, and conclusion mismatch. The result is useful for documentation, and quality checks.

Construction Use Cases

The tool can model jobsite reasoning. For example, if a slab is inspected and inspected work may proceed, then work may proceed. If either temporary bracing is approved or engineered shoring is approved, and both paths justify access, then access is justified. These examples are not legal opinions. They are logic tests that make reasoning visible.

Proof Scope

Fitch proofs use boxes. A box starts with an assumption. Lines inside that box can depend on it. When the box closes, the assumption is discharged by a rule. Conditional introduction is a common case. If assuming A leads to B, the closed proof supports A implies B. The calculator checks this pattern using ranges such as 3-6.

Advanced Checking

Strict scope mode blocks references to hidden lines. This helps prevent a common proof error. A line inside a closed assumption should not support a later main proof line unless a discharge rule permits it. The checker also normalizes symbols. You may type arrows, conjunctions, negations, or plain keyboard versions.

Export And Review

CSV export helps teams keep line results in a spreadsheet. The report download gives a compact review record. It includes the project name, reviewer, premises, conclusion, score, and line feedback. Use these exports during design reviews and classroom demonstrations.

Good Practice

Write short atoms. Use names like PermitApproved, SurveyComplete, or AccessAllowed. Keep one idea per atom. Cite only earlier lines. Enter depth numbers carefully. Review every warning. A valid proof is only as useful as the premises behind it.

FAQs

What is a Fitch proof?

A Fitch proof is a natural deduction proof. It uses numbered lines, rules, references, and subproofs. Each line must follow from earlier allowed lines.

Why is this useful in construction?

Construction decisions often depend on conditions. The calculator helps express those conditions clearly. It can review reasoning about permits, inspections, access, sequencing, and approvals.

What does depth mean?

Depth shows subproof nesting. Use zero for main proof lines. Use one or more when a line sits inside an assumption box.

Which rules are supported?

It supports premise, assumption, reiteration, conjunction, disjunction, conditional, biconditional, negation, double negation, and contradiction rules.

How do I cite a subproof?

Use a range such as 3-6. The first line should be the assumption. The last line should be the result reached under that assumption.

Can I use logic symbols?

Yes. You may type common symbols or keyboard forms. For example, use ~ for not, & for and, | for or, and -> for implies.

Why did my proof fail?

Check the feedback column. Common causes include hidden references, wrong rule names, formula mismatch, invalid ranges, or a final line that does not match the conclusion.

Are the exports created after checking?

Yes. The CSV and PDF buttons process the current form values. They export the latest proof review, line statuses, score, and notes.

Related Calculators

Paver Sand Bedding Calculator (depth-based)Paver Edge Restraint Length & Cost CalculatorPaver Sealer Quantity & Cost CalculatorExcavation Hauling Loads Calculator (truck loads)Soil Disposal Fee CalculatorSite Leveling Cost CalculatorCompaction Passes Time & Cost CalculatorPlate Compactor Rental Cost CalculatorGravel Volume Calculator (yards/tons)Gravel Weight Calculator (by material type)

Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.