Anchor: However, relocation of the air preheater(s) usually is not necessary.
Entailed: There is usually no need to move the air preheater.
Contradiction: It is necessary to move the air preheater.
Contradiction: There were several treaties and when each was signed the border was changed.
Contradiction: A person is holding a guitar.
Contradiction: Robust growth will be achieved by abundant saving.
Contradiction: A black man stands on a boat