A.30 library(option): Option list processing
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Availability::- use_module(library(option)).(can be autoloaded)
Source[det]merge_options(+New, +Old, -Merged)
Merge two option sets. If Old is a dict, Merged is a dict. Otherwise Merged is a sorted list of options using the canonical format Name(Value) holding all options from New and Old, after removing conflicting options from Old.

Multi-values options (e.g., proxy(Host, Port)) are allowed, where both option-name and arity define the identity of the option.