A brother of Colombia's education minister has been killed by Marxist rebels who kidnapped him three years ago.
Three years ago is not equal to four years ago.
( z1 equal :polarity - :ARG1 ( z2 before :op ( z3 now ) :quant ( z4 temporal-quantity :quant 3 :unit ( z5 year ) ) ) :ARG2 ( z6 before :op ( z7 now ) :quant ( z8 temporal-quantity :quant 4 :unit ( z9 year ) ) ) )