Anchor: , magnesium or buffering agents) will reduce the amount of limestone needed.
Entailed: Magnesuim will reduce the amount of limestone needed.
Contradiction: Magnesuim won't reduce the amount of limestone needed.
Contradiction: Bringing home food as souvenirs from your vacation can be a source of headache. 
Contradiction: The practices need a customized application.
Contradiction: He didn't ask any questions and kept silent. 
Contradiction: There is a person laying in the sun