Encyclopedia > Substitution property of equality

  Article Content

Substitution property of equality

In mathematics, the substitution property of equality states:
  • For any quantities a and b and any expression F(x), if a = b, then F(a) = F(b) (if either side makes sense).
In first order logic, this is a schema, since we can't quantify over expressions like F (which would be a functional predicate).

Some specific examples of this are:

  • For any real numbers a, b, and c, if a = b, then a + c = b + c (here F(x) is x + c);
  • For any real numbers a, b, and c, if a = b, then a - c = b - c (here F(x) is x - c);
  • For any real numbers a, b, and c, if a = b, then ac = bc (here F(x) is xc);
  • For any real numbers a, b, and c, if a = b and c is not zero, then a/c = b/c (here F(x) is x/c).

See also: reflexive property of equality, symmetric property of equality, transitive property of equality



All Wikipedia text is available under the terms of the GNU Free Documentation License

 
  Search Encyclopedia

Search over one million articles, find something about almost anything!
 
 
  
  Featured Article
Monty Woolley

... to Dinner[?], which he had performed onstage before taking it to Hollywood. Academy Awards and Nominations 1945 - Nominated - Best Actor in a Supporting Role - Since ...

 
 
 
This page was created in 27.4 ms