Summary of significant accounting policies (Narrative) (Details)	12 Months Ended
Oct. 31, 2019
Patents [Member]
Disclosure Of Summary Of Significant Accounting Policies [Line Items]
Useful lives or depreciation rates, property, plant and equipment	5 years

The useful lives or depreciation rates used for property, plant and equipment. [Refer: Property, plant and equipment]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 16
-IssueDate 2018-01-01
-Paragraph 73
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=16&date=2018-03-01&anchor=para_73_c&doctype=Standard
-URIDate 2018-03-16

Name:	ifrs-full_UsefulLivesOrDepreciationRatesPropertyPlantAndEquipment
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration