Answer
$I_{Z}=
The\,function\,I_{Z}\,is\,called\,the\,identity\,function\,on\,\mathbb{Z}\,\\because\,it\,sends\,each\,element \,\,of\,
\mathbb{Z}\,to\,the\,element\,that\,is\,identical\,to\,it.\\
so\,\,\\
I_{Z}(e)=e \\
I_{Z}(b^{jk}_{i})=b^{jk}_{i} \\
I_{Z}(K(t))=K(t) \\
I_{Z}(u_{kj})=u_{kj} \\
notice\,that\,e\,,b^{jk}_{i},K(t)\,and\,u_{kj}\,\,all\,represent\,\,integers
$
Work Step by Step
$I_{Z}=
The\,function\,I_{Z}\,is\,called\,the\,identity\,function\,on\,\mathbb{Z}\,\\because\,it\,sends\,each\,element \,\,of\,
\mathbb{Z}\,to\,the\,element\,that\,is\,identical\,to\,it.\\
so\,\,\\
I_{Z}(e)=e \\
I_{Z}(b^{jk}_{i})=b^{jk}_{i} \\
I_{Z}(K(t))=K(t) \\
I_{Z}(u_{kj})=u_{kj} \\
notice\,that\,e\,,b^{jk}_{i},K(t)\,and\,u_{kj}\,\,all\,represent\,\,integers
$
