Anchor: The cost models described in appendix II can be used to make a rough estimate of how long a system development may require.
Entailed: Appendix 2 describes various cost models 
Contradiction: The time it takes for a system development can't be estimated. 
Contradiction: Please worry about it. 
Contradiction: There are three children riding outside.
Contradiction: What a grand idea!
Contradiction: Woman holding a book.