# update tutorials

docs/tutorials/add_tei.rst

@@ -12,15 +12,15 @@ over all evolutionary age categories denoted as *phylostra*.
 
 .. math::
 
-    eqn{TEI_s = sum (e_is * ps_i) / sum e_is}
+    TEI_s = sum (e_is * ps_i) / sum e_is
 
-where :math:`eqn{TEI_s}` denotes the TEI value in developmental stage
-:math:`eqn{s, e_is}` denotes the gene expression level of gene :math:`eqn{i}`
-in stage :math:`eqn{s}`, and :math:`eqn{ps_i}` denotes the corresponding phylostratum
-of gene :math:`eqn{i, i = 1,…,N}` and :math:`eqn{N = total number of genes}`.
+where :math:`TEI_s` denotes the TEI value in developmental stage
+:math:`s, e_is` denotes the gene expression level of gene :math:`i`
+in stage :math:`s`, and :math:`eqn{ps_i}` denotes the corresponding phylostratum
+of gene :math:`i, i = 1,…,N` and :math:`N = total number of genes`.
 
 .. note::
-   Please have a look at `Liu & Robinson-Rechavi, 2018<https://doi.org/10.1093/gbe/evy177>`_ to get more insides how expression transformation can influence TEI calculation.
+   Please have a look at `Liu & Robinson-Rechavi, 2018 <https://doi.org/10.1093/gbe/evy177>`_ to get more insides how expression transformation can influence TEI calculation.
    By default, the expression values are pre-processed. This includes normalizing the counts per cell (see option `normalize_total`) to a total count of 1e6 (which corresponds to CPM; see option `target_sum`) and log-transformed (see option `log1p`).
 
 How to add a transcriptome evolutionary index (short: TEI) to scRNA data