Best way to reproduce these graphics?

[andresB]

I would like some advices to reproduce graphics like this. Particularly, I would like that each straight segment has an arrow in the middle.

 

[DrClaude]

Shouldn't be too hard to do using TikZ.

https://en.wikibooks.org/wiki/LaTeX/PGF/TikZhttp://www.texample.net/tikz/examples/snake-lemma/http://www.texample.net/tikz/examples/refraction/

 

[Bill Simpson]

To put arrowheads within a line you might try drawing an arrow set back from the endpoints on top of the line. For example

ar[{p_,q_}]:=Arrow[{p,q},1/4 Norm[q-p]];
Graphics[{
ar[{{0,0},{2,0}}],ar[{{4/3,1},{1,1/8}}],ar[{{1/4,1/8},{1,1/2}}],
Line[{{0,0},{2,0},{2,1},{4/3,1},{1,1/8},{1/4,1/8},{1,1/2},{5/4,9/8},{2,9/8}}]
}]

Depending on how you use this you may have to adjust the amount the arrow is set back