ADVICE on choosing a rule appropriate to the operator '⊃' (IF...THEN)
| suggestions: | ||
| If ⊃ | is the Main Operator in a PREMISE, | MP MT HS |
| the MO in the GOAL or CONCLUSION, | CP HS | |
| to be LEFT AS IS while others change, | EXP TRAN | |
| to be REPLACED with another operator, | IMPL 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.