The privately owned spacecraft only got about 400 feet into space, according to radar measurements, but it was enough to confirm that it no longer takes a well-heeled government project to organize space travel.
The distance the spacecraft got into space was less then 401 feet.
less than 401 is 400 so it is correct but the AI recognized 401 was not 400 and marked it incorrect.
( z1 less-than :op ( z2 distance :extent-of ( z3 get :ARG1 ( z4 spacecraft ) :ARG2 ( z5 space ) ) ) :domain ( z6 distance :extent-of z3 ) )