Used_in The definition of C++ [ c++.syntax.html ]. Used_in The definition of Java [ java.syntax.html ] Notation This uses my XBNF Extended BNF Notation where | indicates or, (...) indicates priority. For more information see [ intro_ebnf.html ].
To look at it in another way: Thymine(uracil in RNA) and cytosine are pyrimidines. Pyrimidines are single-ringed organic base that will only attach to purines, or adenine and guanine by hydrogen bond. Because cytosine and thymine are both pyrimidines, it cannot form a hydrogen bond with each other.
By Yolanda Smith, BPharm. Thymine, which is often abbreviated to T or Thy, can also be referred to as 5-methyluracil. It is one of the pyrimidine bases found in the nucleic acid of DNA, along with adenine, guanine and cytosine (A, G and C).These bases are the building blocks of DNA and life form on earth.t is one of the pyrimidine bases found in the nucleic acid of DNA, along with adenine, guanine and cytosine (A, G and C). These bases are the building blocks of DNA and life form on earth.