constraint vs unresponsiveness

constraint

noun
  • The repression of one's feelings. 

  • An irresistible force or compulsion. 

  • A condition that a solution to an optimization problem must satisfy. 

  • A linkage or other restriction that maintains database integrity. 

  • Something that constrains; a restriction. 

unresponsiveness

noun
  • The state of being unresponsive. 

How often have the words constraint and unresponsiveness occurred in a corpus of books? (source: Google Ngram Viewer )