counterfactual vs null

counterfactual

noun
  • A conditional statement in which the conditional clause is false. 

  • A claim, hypothesis, or other belief that is contrary to the facts. 

  • A hypothetical state of the world, used to assess the impact of an action. 

adj
  • Contrary to known or agreed facts; untrue. 

  • Of or in comparison to a hypothetical state of the world. 

null

noun
  • The null hypothesis. 

  • The null character; the ASCII or Unicode character (␀), represented by a zero value, which indicates no character and is sometimes used as a string terminator. 

  • Zero quantity of expressions; nothing. 

  • One of the beads in nulled work. 

  • A non-existent or empty value or set of values. 

  • Something that has no force or meaning. 

  • The attribute of an entity that has no valid value. 

adj
  • Insignificant. 

  • Having no validity; "null and void". 

  • Causing a complete loss of gene function; amorphic. 

  • Absent or non-existent. 

  • Of the null set. 

  • Of or comprising a value of precisely zero. 

  • Neutral. 

verb
  • To crack; to remove restrictions or limitations in (software). 

  • To return to the null position, setting, etc. 

  • To form nulls, or into nulls, as in a lathe. 

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