if the fact that the counterglow does not occur and the settling does not occur does not hold then the intermediate does not occur.
sent1: the counterglow does not occur and the settling does not occur if the antiviral occurs. sent2: if the antiviral does not occur then the intermediate does not occur.
void -> assump2: Let's assume that the fact that the antiviralness occurs hold.; sent1 & assump2 -> int1: the counterglow does not occur and the settling does not occur.; void -> assump1: Let's assume that that the counterglow does not occur and the settling does not occur is incorrect.; int1 & assump1 -> int2: this is contradiction.; [assump2] & int2 -> int3: the antiviralness does not occur.; sent2 & int3 -> int4: the intermediateness does not occur.; [assump1] & int4 -> hypothesis;
$hypothesis$ = if the fact that the counterglow does not occur and the settling does not occur does not hold then the intermediate does not occur. ; $context$ = sent1: the counterglow does not occur and the settling does not occur if the antiviral occurs. sent2: if the antiviral does not occur then the intermediate does not occur. ; $proof$ = 
void -> assump2: Let's assume that the fact that the antiviralness occurs hold.; sent1 & assump2 -> int1: the counterglow does not occur and the settling does not occur.; void -> assump1: Let's assume that that the counterglow does not occur and the settling does not occur is incorrect.; int1 & assump1 -> int2: this is contradiction.; [assump2] & int2 -> int3: the antiviralness does not occur.; sent2 & int3 -> int4: the intermediateness does not occur.; [assump1] & int4 -> hypothesis; __PROVED__