# Documentation

## Lean.Meta.Tactic.UnifyEq

Instances For
def Lean.Meta.unifyEq? (mvarId : Lean.MVarId) (eqFVarId : Lean.FVarId) (subst : optParam Lean.Meta.FVarSubst { map := }) (acyclic : optParam () fun (x : Lean.MVarId) (x : Lean.Expr) => ) (caseName? : optParam none) :

Helper method for methods such as Cases.unifyEqs?. Given the given goal mvarId containing the local hypothesis eqFVarId, it performs the following operations:

• If eqFVarId is a heterogeneous equality, tries to convert it to a homogeneous one.
• If eqFVarId is a homogeneous equality of the form a = b, it tries
• If a and b are definitionally equal, clear it
• Normalize a and b using the current reducibility setting.
• If a (b) is a free variable not occurring in b (a), replace it everywhere.
• If a and b are distinct constructors, return none to indicate that the goal has been closed.
• If a and b are the same constructor, apply injection, the result contains the number of new equalities introduced in the goal.
• It also tries to apply the given acyclic method to try to close the goal. Remark: It is a parameter because simp uses unifyEq?, and acyclic depends on simp.
Equations
• One or more equations did not get rendered due to their size.
Instances For
def Lean.Meta.unifyEq?.substEq (mvarId : Lean.MVarId) (eqFVarId : Lean.FVarId) (subst : optParam Lean.Meta.FVarSubst { map := }) (acyclic : optParam () fun (x : Lean.MVarId) (x : Lean.Expr) => ) (eqDecl : Lean.LocalDecl) (a : Lean.Expr) (b : Lean.Expr) (symm : Bool) :
Equations
• One or more equations did not get rendered due to their size.
Instances For
def Lean.Meta.unifyEq?.injection (mvarId : Lean.MVarId) (eqFVarId : Lean.FVarId) (subst : optParam Lean.Meta.FVarSubst { map := }) (caseName? : optParam none) (eqDecl : Lean.LocalDecl) (injectionOffset? : ) (a : Lean.Expr) (b : Lean.Expr) :
Equations
• One or more equations did not get rendered due to their size.
Instances For