These are cells

5345+5325

Plus[5345,5325]

ab

ab+a

a b+a b+ab

Simplify[2a b+ a^2+ b^2]

?Simplify

3!

120!

23./123

(23./123-23/123)/(23/123)

Pi

α + β -α

2 Pi

2. Pi

Sin[Pi]

Sin[1. Pi]

Sin[N[Pi]]

Pi.

Pi=3.14

Pi

N[Pi]

Sin[a]

Sin[a+b]

Sin[a,b]

( ) (* precedence *)

[]  (* function call *)

{}  (* list constructor *)

[[ ]]  (* access *)

(* comment *)

123!

2^1024.

N[123!]

(N[123!,16]-123!)/123!

N[a+b]

N[Pi,1000]

Pi^E

Pi^Pi

E

I

Sqrt[-3]

?Plot*

?*Plot

?*Permut*

?E

Cos[4.5]
Cos@4.5
4.5//Cos

N[1234!]

N[123/124,100]

sin[a]

sin[Pi]

Sin[sin[Pi]]

{1,2,3,4}

{{1,2,3,4}[[2]],3,-1}[[-3]]

{1,2,x,Pi,Sin}

{{1,2,3},{4,5},{6,7,8}}

{1,2,3,4}//MatrixForm

Transpose[{1,2,3,4}]

{{1,2,3,4},{a,b,c,d}}//MatrixForm

Transpose[{{1,2,3,4},{a,b,c,d}}]//MatrixForm

{{1,2,3,4}}//MatrixForm

{{1,2,3,4}}//Transpose//MatrixForm

{1,2,x,Pi,Sin}[[5]][Pi]

a{1,2,3,4}

{a,b,c,d}+{1,2,3,4}

a+{1,2,3,4}

{1,2,3}+{a,b,c,d}

Sin[a,Sin][[2]][Pi/2,b]

Sin[a,b][[0]]

List[a,b,3,4,Pi]

{a,b,3,4,Pi}[[0]]

{a,b,Sin[3],4^Pi}//TreeForm

({a,b,Sin[3],4^Pi}//TreeForm)[[0]]

TreeForm[{a,b,Sin[3],4^Pi}][[0]]

{1,2,3}*{a,b,c}

{1,2,3}*{a,b}

{1,2,3}^{a,b,c}

{{c,d}}.{{a},{b}}

?FixedPoint

N[Pi,1000]