Anchor: They failed, though one effort was close enough, but their attempts would not have been made at all if they had not been convinced through their arts that you can succeed with the sky."  Dave shook his head.
Entailed: They had failed on their first try. 
Contradiction: They succeeded their first time. 
Contradiction: Some boys are sleeping
Contradiction: A brown dog leaps.
Contradiction: A young boy playing in a wading pool.
Contradiction: When posturing about Southern truckstop/trailer park chic one should be aware that all they are doing is posturing.