Discussions related to Visual Prolog
Wabbit
Posts: 3
Joined: 24 Apr 2023 12:25

The flow pattern '(o,o)' does not exist - I must be blind

Unread post by Wabbit »

I am getting this error: The flow pattern '(o,o)' does not exist for 'main::heal/2'

The logic goal is to find the modifier that shifts a taxon in the right direction. I was an old Borland TurboProlog user and trying to revive old memory cells.

Code: Select all

class facts - taxonDB     increases : (integer Modifier, integer Taxon).     decreases : (integer Modifier, integer Taxon).     high : (string Person, integer Taxon).     low : (string Person, integer Taxon).   class predicates     heal : (string Person, integer Modifier). clauses     heal(Person, Modifier) :-         increases(Modifier, Taxon),         low(Person, Taxon).
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Gukalov
VIP Member
Posts: 62
Joined: 5 Oct 2011 15:16

Re: The flow pattern '(o,o)' does not exist - I must be blind

Unread post by Gukalov »

Code: Select all

class predicates     heal : (string Person, integer Modifier) nondeterm (o, o).
Turbo: all the predicates are "nondeterm", no matter an argument is IN or OUT
VIP: it need to define determ/nondeterm/procedure... arguments IN/OUT
If you don't define, VIP takes the predicate as procedure with arguments IN.

https://wiki.visual-prolog.com/index.ph ... icate_Mode

It can disturb while switching from Turbo to VIP, but not a long time according my own experience)))
Wabbit
Posts: 3
Joined: 24 Apr 2023 12:25

Re: The flow pattern '(o,o)' does not exist - I must be blind

Unread post by Wabbit »

Many thanks.
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