In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: Decompression and neurolysis were performed with good subsequent recovery of function .
### Output Text:
Decompression and neurolysis were performed with good subsequent recovery of function . 