example : ((p ∨ q) → r) → (p → r) ∧ (q → r)...

example: (p ∨ q) ∧ (p ∨ r) → p ∨ (q ∧ r)...

Defining a function to a subset of the codomain...

Lean Mergesort using increasing well founded relation...

Does lean have syntax for declaration of signatures?...

What makes the natural numbers so special with regards to timing out?...

How to leave out a part of programming code, in a programming code quote?...

Trouble defining a subset of Euclidean space...

Proving substitution property of successor over equality...

Beginner, cannot import in Lean...

Representing a theorem with multiple hypotheses in Lean (propositional logic)...

Recovering nat from a positive integer in Lean...

Why doesn't this dual poset definition don't type check...

Dependently typed bounded range in Lean...

Painless way to show simple inequality over whole number...

Equality in definitions (decidable equality? e.g. replace elements in list)...

Testing polynomial definition (from natural numbers to integers)...

Defining the predecessor function (with pred 0 = 0) for the natural numbers in Lean...

From set inclusion to set equality in lean...

Using sets in lean...

lean : eq.subst chokes on h:(n=0)...

How to write a definition of the non-dependent product using Pi types in Lean?...

How to prove a relation at compile-time in Lean?...

How to pattern match on a Prop when proving in Coq without elimination on Type...

In Lean, is it possible to use decidable_linear_order with a user defined equality relation?...

How to propogate an assumption when pattern matching in Lean...

Attaching an attribute to a definition causes syntax errors...

Why do Leans `Prop`ositions get special treatment?...

Inductive type constructed by a list of that type in Lean...

How to define mutual inductive propositions in Lean?...