% Proven with SWI-Prolog https://www.swi-prolog.org/
% including check for tautology

% label

% label("Contraction of the Arctic Ice | Climatology | Measurements Polar Ice Arctic| D.V.",urlSVG,"https://danielverhoeven.deds.nl/dag/smelten_noordpoolkap/Arctic_Shrinking_datalog.svg).


% facts

url("https://en.wikipedia.org/wiki/Arctic").
url("https://nsidc.org/arcticseaicenews/2023/09/").
url("https://www.ipcc.ch/report/sixth-assessment-report-cycle/").
average_temperature("arctic_circle < 0&deg;C",1980).
average_temperature("arctic_circle > 0&deg;C",2016).
volume(arctic_ice,"zero_measurement",1980).
volume(arctic_ice,"zero_measurement - 7500 billion tons",2016).
surface(arctic_ice,"7,54 million kmē",1980).
surface(arctic_ice,"4,17 million kmē",2016).

% rules
% rule checking for tautology
different(X, X) :- !, fail.
different(X, Y).

% rules for causation graphs
prove :- process(contraction,climate_change,arctic_ice).

process(contraction,climate_change,arctic_ice) :-
	url("https://www.ipcc.ch/report/sixth-assessment-report-cycle/"),
	different(status(storage,snow,arctic_ice,1980),status(storage,snow,arctic_ice,2016)),
	status(storage,snow,arctic_ice,1980),
	status(storage,snow,arctic_ice,2016).

status(storage,snow,arctic_ice,2016) :-
	url("https://nsidc.org/arcticseaicenews/2023/09/"),
	average_temperature("arctic_circle > 0&deg;C",2016),
	volume(arctic_ice,"zero_measurement - 7500 billion tons",2016),
	surface(arctic_ice,"4,17 million kmē",2016).

status(storage,snow,arctic_ice,1980) :-
	url("https://en.wikipedia.org/wiki/Arctic"),
	average_temperature("arctic_circle < 0&deg;C",1980),
	volume(arctic_ice,"zero_measurement",1980),
	surface(arctic_ice,"7,54 million kmē",1980).