proof.sty: A User Guide

4. Further tricks and tips

a To centre proofs with spacing above and below, place in a standard mathmode context '$$....$$'. More than one proof in the same context will be set with their conclusions aligned: the proofs can be spaced using e.g. '\quad'. For example:

 $$\infer[(\to I)] {(A \to B)} { \infer*{B}{[A]} } \qquad \infer[(\to E)] {B} {(A \to B) & A}$$

b If a proof is set in-line, then its conclusion sits on the current line and the rest of the proof is above the line. To centre a proof vertically, you can use the TeX command '\vcenter'. For instance ...

 The rule $\vcenter{\infer {(A \to B)} { \infer*{B}{[A]} }}$is known as $\to$-introduction

c Other TeX commands (particularly '\kern') can be used for horizontal fine-tuning. Interline vertical spacing within a proof is controlled by the dimension 'inferLineSkip' whose default value is 2 pt. To increase this you can prefix your proof with e.g. '\inferLineSkip=4pt'.

5. Limitations/unwanted features (next page)