Introduces a formula into the antecedent of a sequent.
Introduces a formula into the antecedent of a sequent. This method merely returns an extended sequent, not a proof.
The sequent whose antecedent is to be weakened.
The formula to introduce into s1.
The sequent s1, with the antecedent extended by f.
Introduces a formula into the left side of a sequent. The rule: (rest of s1) sL |- sR ------------ (WeakeningLeft) sL, f |- sR
Introduces a formula into the left side of a sequent. The rule: (rest of s1) sL |- sR ------------ (WeakeningLeft) sL, f |- sR
The top proof with (sL |- sR) as the bottommost sequent.
The formula to introduce below s1.
An LKProof ending with the new inference.