ADVICE on choosing a rule appropriate to the operator '≡' (EQUIV)
| suggestions: | ||
| If ≡ | is the Main Operator in a PREMISE, | EQUIV |
| the MO in the GOAL or CONCLUSION, | EQUIV | |
| to be LEFT AS IS while others change, | cannot be done | |
| to be REPLACED with another operator, | EQUIV DN TAUT |
Note: if the conclusion or goal proposition is IDENTICAL to a portion of a premise, then chose the rule according to that PREMISE'S main operator.