Northern Ireland- 2nd August 2013 Mandatory Credit - Photo-Jonathan Porter/Presseye. 2013 World Police and Fire Games Track and Field event at Dame Mary Peters' Track in Finaghy. 100m event.

Robert Doggart from Northern Ireland pictured at the Small bore rifles at the World Police and Fire games held at Ballykinler army barracks in County Down Picture by Stephen Hamilton/Presseye.com

Northern Ireland- 2nd August 2013 Mandatory Credit - Photo-Jonathan Porter/Presseye. 2013 World Police and Fire Games Track and Field event at Dame Mary Peters' Track in Finaghy. 100m event.

World Police & Fire Games - Dragon Boat Race - Waterfront - Presseye - Saturday 3rd August 2013 York dragons who finished third in the race

World Police & Fire Games - Dragon Boat Race - Waterfront - Presseye - Saturday 3rd August 2013 Sinagapore dragons who finished second in the race to Germany

World Police & Fire Games - GAA Queens DUB - Presseye - Saturday 3rd August 2013 Copyright Presseye / Declan Roughan Donegal GARDA's Neil Cox and Irish Prison Service's Paurig Carthy and Ray Cox in action in Saturdays final.

The Stair Climb is one of the most physically demanding competitive events in the World Police and Fire Games. It will take place on Sunday 4th August at the Obel Building when firefighters will race up the 27 storey building against the clock. In all they will climb 550 steps wearing full structural firefighting gear including breathing equipment. The fittest men and women will be aiming to complete the climb in around 5 minutes. Picture by Matt Mackey/Presseye.com

World Police and Fire Games 2013 Tug of War Competition at Stormont Estate Competitors from Norway Picture by Kelvin Boyes / Press Eye.

World Police and Fire Games 2013 Tug of War Competition at Stormont Estate Picture by Kelvin Boyes / Press Eye.

World Police and Fire Games 2013 Tug of War Competition at Stormont Estate Spectators Picture by Kelvin Boyes / Press Eye.

World Police and Fire Games 2013 Tug of War Competition at Stormont Estate Competitors from Norway Picture by Kelvin Boyes / Press Eye.

World Police and Fire Games 2013 Tug of War Competition at Stormont Estate Spectators Picture by Kelvin Boyes / Press Eye.

World Police and Fire Games 2013 Tug of War Competition at Stormont Estate Republic of Ireland Competitors Picture by Kelvin Boyes / Press Eye.

World Police and Fire Games 2013 Bodybuilding Competition at the Waterfront Hall, Belfast Overall bodybuilding winner Othman Yahya from Malaysia Picture by Kelvin Boyes / Press Eye.

World Police and Fire Games 2013 Bodybuilding Competition at the Waterfront Hall, Belfast General views of competitors. Picture by Kelvin Boyes / Press Eye.

World Police and Fire Games 2013 Bodybuilding Competition at the Waterfront Hall, Belfast General views of competitors. Picture by Kelvin Boyes / Press Eye.

World Police and Fire Games 2013 Bodybuilding Competition at the Waterfront Hall, Belfast General views of competitors. Picture by Kelvin Boyes / Press Eye.

World Police and Fire Games 2013 Bodybuilding Competition at the Waterfront Hall, Belfast Overall bodybuilding winner Othman Yahya from Malaysia Picture by Kelvin Boyes / Press Eye.

World Police and Fire Games 2013 Bodybuilding Competition at the Waterfront Hall, Belfast General views of competitors. Picture by Kelvin Boyes / Press Eye.

Paul Mulcahy from Ireland (white belt) against Talgat Kazhabaeb from Kazakhstan (blue belt) pictured at the World Police and Fire games judo event held at the Shankill Leisure centre in Belfast. Press Eye Ltd Northern Ireland

Rob Cullen from Canada pictured at the World Police and Fire games held at the Ballyholme Sailing club in Bangor Co Down Picture by Stephen Hamilton/Presseye.com

Robin Gray briefs sailors of a delay to proceedings at the World Police and Fire games held at the Ballyholme Sailing club in Bangor Co Down Picture by Stephen Hamilton/Presseye.com

John McVea from Northern Ireland pictured at the World Police and Fire games held at the Ballyholme Sailing club in Bangor Co Down Picture by Stephen Hamilton/Presseye.com

Thierry Delhief from French Polenesia against Colin McDonald from Northern Ireland pictured at the World Police and Fire games Karate event held at the Shankill Leisure centre in Belfast Picture by Stephen Hamilton/Presseye.com

Rob Cullen from Canada pictured at the World Police and Fire games held at the Ballyholme Sailing club in Bangor Co Down Picture by Stephen Hamilton/Presseye.com

Elaine Betts pictured with Judith Gillespie and Dame Mary Peters at the World Police and Fire games held at the Aurora swimming centre in Bangor Co Down after coming second in the 800 metres swimming. Picture by Stephen Hamilton/Presseye.com

Sharon Cooper from Northern Ireland pictured at the World Police and Fire games held at the Aurora swimming centre in Bangor Co Down Picture by Stephen Hamilton/Presseye.com

Sinead Tyrrell from the Gardai Siochana pictured at the World Police and Fire games held at the Aurora swimming centre in Bangor Co Down Picture by Stephen Hamilton/Presseye.com

Eighty year old Charlie Weatherby from Florida fire department pictured at the World Police and Fire games held at the Aurora swimming centre in Bangor Co Down Picture by Stephen Hamilton/Presseye.com

Petra Nentwich pictured at the World Police and Fire games held at the Aurora swimming centre in Bangor Co Down Picture by Stephen Hamilton/Presseye.com

World Police and Fire games held at the Aurora centre in Bangor Co Down ,Northern Ireland PSNI v Northern Ireland Fire service in the third place play off. PSNI's Stephanie Carson with NI Fire services Naebh Dunn Picture by Stephen Hamilton/Presseye.com

World Police and Fire Games 2013 Bodybuilding Competition at the Waterfront Hall, Belfast General views of competitors. Picture by Kelvin Boyes / Press Eye.

2013 World Police and Fire Games Track and Field event at Dame Mary Peters' Track in Finaghy. USA's Charles Williams(second from right) from the LAPD takes part in the 100m event.

David Anderson from Northern Ireland pictured at the World Police and Fire games held at the Ballyholme Sailing club in Bangor Co Down Picture by Stephen Hamilton/Presseye.com

Sailors and volunteers pictured at the World Police and Fire games held at the Ballyholme Sailing club in Bangor Co Down Picture by Stephen Hamilton/Presseye.com

World Police and Fire games Karate event held at the Shankill Leisure centre in Belfast Picture by Stephen Hamilton/Presseye.com Thierry Delhief from French Polenesia against Colin McDonald from Northern Ireland

Northern Ireland- 2nd August 2013, Photo-Jonathan Porter/Presseye. 2013 World Police and Fire Games Track and Field event at Dame Mary Peters' Track in Finaghy. A competitor takes part in the the Long Jump as part of the Decathlon event.

Northern Ireland- 2nd August 2013, Photo-Jonathan Porter/Presseye. 2013 World Police and Fire Games Track and Field event at Dame Mary Peters' Track in Finaghy. A competitor takes part in the the Long Jump as part of the Decathlon event.

Northern Ireland- 2nd August 2013, Photo-Jonathan Porter/Presseye. 2013 World Police and Fire Games Track and Field event at Dame Mary Peters' Track in Finaghy. Northern Ireland firefighter Brendan McConville takes part in the Long Jump as part of the Decathlon event.

WorldPolice & Fire Games - Mary Peters Track Belfast - Presseye - Saturday 3rd August 2013 Brendan Mc Conville with his two boys Troy (left) and Lex

WorldPolice & Fire Games - Mary Peters Track Belfast - Presseye - Saturday 3rd August 2013 NIFS Brendan Mc Conville warms up for the 110 meter hurdles in the Decathlon

WorldPolice & Fire Games - Mary Peters Track Belfast - Presseye - Saturday 3rd August 2013 Daniel Soriesanga from Bucharest prepares to go in the 110 meter hurdles Decathlon

WorldPolice & Fire Games - Mary Peters Track Belfast - Presseye - Saturday 3rd August 2013 Jackie Houst from the USA prepares to go in the 110 meter hurdles Decathlon

WorldPolice & Fire Games - Mary Peters Track Belfast - Presseye - Saturday 3rd August 2013 Lewis and Mum Nadine Mercer enjoy the games at the Mary Peters track

Northern Ireland- 2nd August 2013, Photo-Jonathan Porter/Presseye. 2013 World Police and Fire Games Dragon Boat Race on the River Lagan behind the Waterfront Hall in Belfast City Centre. The Irish Prison Service Dragon Boat team.

Northern Ireland- 2nd August 2013, Photo-Jonathan Porter/Presseye. 2013 World Police and Fire Games Dragon Boat Race on the River Lagan behind the Waterfront Hall in Belfast City Centre. The race gets under way.

World Police and Fire Games 2013 Tug of War Competition at Stormont Estate Competitors from Norway Picture by Kelvin Boyes / Press Eye.

2013 World Police and Fire Games Track and Field event at Dame Mary Peters' Track in Finaghy. Northern Ireland firefighter Brendan McConville takes part in the Long Jump as part of the Decathlon event.

World Police and Fire Games 2013 Bodybuilding Competition at the Waterfront Hall, Belfast Overall bodybuilding winner Othman Yahya (centre) from Malaysia Picture by Kelvin Boyes / Press Eye.

WorldPolice & Fire Games - Mary Peters Track Belfast - Presseye - Sunday 4th August 2013 Copyright Presseye / Declan Roughan Jim Currell, 400 meter compeditor with his wife Janet both from Austrailia

PACEMAKER, BELFAST, 5/8/2013: You're nicked! PSNI Chief Constable Matt Baggott catches a fish during the World Police and Fire Games Pairs Fly Fishing competition at Killylane reservoir near Ballymena today. PICTURE BY STEPHEN DAVISON

Festival of Kites on Sunday at Downhill and Mussenden Temple (national trust properties) in Co-Derry. Picture Margaret McLaughlin © by-line 4-8-13

Festival of Kites on Sunday at Downhill and Mussenden Temple (national trust properties) in Co-Derry. Picture Margaret McLaughlin © by-line 4-8-13

©Press Eye Ltd Northern Ireland 4th August 2013 - Mandatory Credit - Picture by Matt Mackey/Presseye.com World Police and Fire Games 2013 Cricket at Stormont Pavilion. South Australia Met fire service v Combined services.

©Press Eye Ltd Northern Ireland 4th August 2013 - Mandatory Credit - Picture by Matt Mackey/Presseye.com World Police and Fire Games 2013 Cricket at Stormont Pavilion. South Australia Met fire service v Combined services.

©Press Eye Ltd Northern Ireland 4th August 2013 - Mandatory Credit - Picture by Matt Mackey/Presseye.com World Police and Fire Games 2013 Mixed Hockey at Stormont Pavilion. PSNI v Garda.

©Press Eye Ltd Northern Ireland 4th August 2013 - Mandatory Credit - Picture by Matt Mackey/Presseye.com World Police and Fire Games 2013 Mixed Hockey at Stormont Pavilion. PSNI v Garda.

©Press Eye Ltd Northern Ireland 4th August 2013 - Mandatory Credit - Picture by Matt Mackey/Presseye.com World Police and Fire Games 2013 at the Bangor Aurora Aquatic & Leisure Complex where athletes from Germany, India and Japan and many others are competing. 200m freestyle. Stephen McConnell from PSNI.

©Press Eye Ltd Northern Ireland 4th August 2013 - Mandatory Credit - Picture by Matt Mackey/Presseye.com World Police and Fire Games 2013 at Darts at Newforge country club.

©Press Eye Ltd Northern Ireland 4th August 2013 - Mandatory Credit - Picture by Matt Mackey/Presseye.com World Police and Fire Games 2013 at Darts at Newforge country club.

©Press Eye Ltd Northern Ireland 4th August 2013 - Mandatory Credit - Picture by Matt Mackey/Presseye.com World Police and Fire Games 2013 at Darts at Newforge country club.

Pacemaker Press 5/8/2012 Fire fighters during The Muster competition as part of The World Police and Fire games at Titanic Slipway in Belfast on monday Pic Colm Lenaghan/Pacemaker

Pacemaker Press 5/8/2012 Spectators take cover from a fire hose during The Muster competition as part of The World Police and Fire games at Titanic Slipway in Belfast on monday Pic Colm Lenaghan/Pacemaker

Pacemaker Press 5/8/2012 Spectators take cover from a fire hose during The Muster competition as part of The World Police and Fire games at Titanic Slipway in Belfast on monday Pic Colm Lenaghan/Pacemaker

Pacemaker Press Belfast 26-07-2013: Pictured cheering on the Team Northern Ireland at the launch of the 2013 World Police and Fire Games Team kit are: Left to Right Mark Cushnahan, (Northern Ireland Fire and Rescue Service), Diane Phillips (Northern Ireland Prison Service), Constable Morena Thomas and Constable Graeme Philson (Police Service of Northern Ireland), Neab Caughey (Northern Ireland Fire and Rescue Service) and Eric Winterbottom (Northern Ireland Prison Service). ÊThe Games take place from the 1 - 10 August and all events are free for the public to attend. Picture By: Pacemaker.

Pacemaker Press 5/8/2012 Spectators take cover from a fire hose during The Muster competition as part of The World Police and Fire games at Titanic Slipway in Belfast on monday Pic Colm Lenaghan/Pacemaker

Pacemaker Press 5/8/2012 Fire fighters from Barcelona during The Muster competition as part of The World Police and Fire games at Titanic Slipway in Belfast on monday Pic Colm Lenaghan/Pacemaker

Pacemaker Press 5/8/2012 Spectators take cover from a fire hose during The Muster competition as part of The World Police and Fire games at Titanic Slipway in Belfast on monday Pic Colm Lenaghan/Pacemaker

Pacemaker Press 5/8/2012 Fire fighters during The Muster competition as part of The World Police and Fire games at Titanic Slipway in Belfast on monday Pic Colm Lenaghan/Pacemaker

PACEMAKER, BELFAST, 5/8/2013: You're nicked! PSNI Chief Constable Matt Baggott competing in the World Police and Fire Games Pairs Fly Fishing competition at Killylane reservoir near Ballymena today. PICTURE BY STEPHEN DAVISON

PACEMAKER, BELFAST, 5/8/2013: PSNI Chief Constable Matt Baggott has an audience as he casts during the World Police and Fire Games Pairs Fly Fishing competition at Killylane reservoir near Ballymena today. PICTURE BY STEPHEN DAVISON

PACEMAKER, BELFAST, 5/8/2013: PSNI Chief Constable Matt Baggott during the World Police and Fire Games Pairs Fly Fishing competition at Killylane reservoir near Ballymena today. PICTURE BY STEPHEN DAVISON

PACEMAKER, BELFAST, 5/8/2013: You're nicked! PSNI Chief Constable Matt Baggott catches a fish during the World Police and Fire Games Pairs Fly Fishing competition at Killylane reservoir near Ballymena today. PICTURE BY STEPHEN DAVISON

PACEMAKER, BELFAST, 5/8/2013: You're nicked! PSNI Chief Constable Matt Baggott catches a fish during the World Police and Fire Games Pairs Fly Fishing competition at Killylane reservoir near Ballymena today. PICTURE BY STEPHEN DAVISON

Pacemaker Press 5/8/2012 Spectators take cover from a fire hose during The Muster competition as part of The World Police and Fire games at Titanic Slipway in Belfast on monday Pic Colm Lenaghan/Pacemaker

Chloe Quinn helps businessman Neville Moore of department store the White House in Portrush get ready for the World Police and Fire Games. With thousands of visitors expected to make their way to Portrush for the three beach events from August 6 - 8 Neville is hopeful of a boost to local business

Pacemaker Press 5/8/2012 Spectators take cover from a fire hose during The Muster competition as part of The World Police and Fire games at Titanic Slipway in Belfast on monday Pic Colm Lenaghan/Pacemaker

Fire fighters during The Muster competition as part of The World Police and Fire games at Titanic Slipway in Belfast. Pic Colm Lenaghan/Pacemaker

Northern Ireland- 1st August 2013 Mandatory Credit - Photo-Jonathan Porter/Presseye. 013 World Police and Fire Games Opening Ceremony at the Kings Hall Complex Belfast. Canadian soccer players toast the start of the games in the arena.

@Press Eye Ltd Northern Ireland- 5th August 2013 Mandatory Credit - Brian Little/ Presseye World Police and Fire Games Cycling Criterium at Stormont Estate, Belfast.

@Press Eye Ltd Northern Ireland- 5th August 2013 Mandatory Credit - Brian Little/ Presseye World Police and Fire Games Robert Boyce (Northern Ireland ) in the wheel of Jose Angel Izaguirre San Emeterio (Spain) during the 55-59/ 50-54 race at the Cycling Criterium at Stormont Estate, Belfast.

WorldPolice & Fire Games - Tennis Belfast Boat Club - Presseye - Monday 5th August 2013 Copyright Presseye / Declan Roughan Belfast Boat Club Tennis Tournament for the WPFG (L-R) Carolin Zuplis and Merianne Freshette bothh from Qubec, Canada

Presseye Northern Ireland - 05th August 2013 Mandatory Credit - Photo-William Cherry/Presseye 2013 World Police and Fire Games - Volleyball Cllr. Alderman Paul Porter with competitors and volunteers in the WPFG Volleyball at Lisburn Racquets.

WorldPolice & Fire Games - Tennis Belfast Boat Club - Presseye - Monday 5th August 2013 Copyright Presseye / Declan Roughan Belfast Boat Club Tennis Tournament for the WPFG (L-R) Mark Richter, Rasin Roman and Christof Seawald all police Germany

WorldPolice & Fire Games - Soccer QUB DUB - Presseye - Monday 5th August 2013 Copyright Presseye / Declan Roughan Brazil State Police against Mexico Corrections Brazil get into the spirit at the Dub yesterday

WorldPolice & Fire Games - Soccer QUB DUB - Presseye - Monday 5th August 2013 Copyright Presseye / Declan Roughan Brazil State Police against Mexico Corrections Brazil get into the spirit at the Dub yesterday

@Press Eye Ltd Northern Ireland- 5th August 2013 Mandatory Credit - Brian Little/ Presseye World Police and Fire Games Lewis Ferguson from Bangor winning silver in the 18-29 race at the Cycling Criterium at Stormont Estate, Belfast.

Fire fighters during The Ultimate Fire fighter competition as part of The World Police and Fire games at Titanic Slipway in Belfast on tuesday Pic Colm Lenaghan/Pacemaker

A Spectator cheers on Fire fighters during The Ultimate Fire fighter competition as part of The World Police and Fire games at Titanic Slipway in Belfast on tuesday Pic Colm Lenaghan/Pacemaker

World Police and Fire games at Mary Peters Track in Belfast. Maria Machin and Jack House from Seattle Picture by Stephen Hamilton/Presseye.com

World Police and Fire games semi final match between Tartarstan Republic Police and Securite Incendie Montreal held at Odyssey Belfast. Picture by /Presseye.com

Soccer finals at the DUB playing fields in South Belfast. PSNI(green) Vs Mexico Police. Mexico win 0-2 to take gold.

Axel Neumann from Germany takes part in the tennis competition at the Belfast Boat CLub.

Womens 300m hurdles during the Track and Field at Mary Peters Track at the 2013 World Police and Fire Games

Ross McClean wins silver medal in the shot put at the Track and Field at Mary Peters Track at the 2013 World Police and Fire Games

Track and Field at Mary Peters Track at the 2013 World Police and Fire Games

Track and Field at Mary Peters Track at the 2013 World Police and Fire Games

Firefighter Gary Parker(blue) from Northern Road Fire Station in Derry plays policeman Henry Lee from Singapore in the squash competition at the Belfast Boat Club. Photo-Jonathan Porter/Presseye.

WPFG Ultimate Fire Fighter on the Titanic Slip Way in Belfast.Picture by Matt Mackey/Presseye.com

Park Special School pupils Sam McGarrigle, Shannon McShane and Lois McNeill celebrate with their World Police and Fire Games buddy Australian Customs Officer, Scott Clayton who won bronze in the final of the 800 metres. Also in the picture is teacher Ali Caldwell and World Police and Fire Games Federation President Mike Graham.Picture by Matt Mackey/Presseye.com

Toughest competitor alive,World Police and Fire games held at Bangor's Aurora centre, Poncho Jacko from Canada Picture by Stephen Hamilton/Presseye.com

Surfing - Women's Short and Longboard at Portrush. Eva Grady from the California State Forestry Fire Departmant Picture Rowland White/Presseye

Soccer finals at the DUB playing fields in South Belfast - Ladies finals. Toronto Police take silver.

World Police and Fire games semi final match between Tartarstan Republic Police and Securite Incendie Montreal held at Odyssey Belfast. Picture by /Presseye.com

Womens 300m hurdles during the Track and Field at Mary Peters Track at the 2013 World Police and Fire Games

Young spectators watch on at Fire fighters during The Ultimate Fire fighter competition as part of The World Police and Fire games at Titanic Slipway in Belfast on tuesday Pic Colm Lenaghan/Pacemaker

The World Police and Fire Games Volleyball at East Strand, Portrush on Wednesday. Picture Margaret McLaughlin

Brazil versus Spain during the World Police and Fire Games' Beach Volleyball event at Portrush's East Strand. Picture Charles McQuillan/Pacemaker

Fire fighters during The Ultimate Fire fighter competition as part of The World Police and Fire games at Titanic Slipway in Belfast on Tuesday Pic Colm Lenaghan/Pacemaker

Brazil versus Spain during the World Police and Fire Games' Beach Volleyball event at Portrush's East Strand. Picture Charles McQuillan/Pacemaker

World Police and Fire Games. Isabelle Perreault centre fielder for Team Quebec women's police team playing in the Softball tournament Queens Dub playing fields. Photo Brian Little/ Presseye

Ultimate Firefighter competition at the Titanic Slipway in the Titanic Quarter of Belfast City Centre. Simone Fitzgerald(5) and her younger sister Robyn(3) from Belfast cheer on their firefighter father Conor. Photo-Jonathan Porter/Presseye.

Big Cheers for Team 2013 Volunteers! Sports Minister, Carál Ní Chuilín and Wendy Osborne, Chief Executive Volunteer Now thank Lee Campbell, Volunteer Support Team Leader and volunteers from Team 2013 for all their commitment and enthusiasm during 2103 World, Police and Fire Games. Photo-William Cherry/Presseye

Ultimate Firefighter competition at the Titanic Slipway in the Titanic Quarter of Belfast City Centre. Local firefighter Conor Fitzgerald takes part in the event. Photo-Jonathan Porter/Presseye.

World Police & Fire Games - Wrestling at Shankill LC. Vikramgeet Vikramgeet from India and Mika Kuroen Finland in the mens 96k Presseye / Declan Roughan

Winners Garda celebrate their victory along with Carl N Chuiln, Minister of Culture, Arts and Leisure for Northern Ireland and NIFRS who took the sliver medal in the GAA final. Picture by Matt Mackey/Presseye.com

GAA at the Dub playing fields in South Belfast. Garda v NIFRS in the GAA final. Picture by Matt Mackey/Presseye.com

Winners Garda celebrate their victory over NIFRS in the GAA final in Belfast. Picture by Matt Mackey/Presseye.com

Ultimate Firefighter competition at the Titanic Slipway in the Titanic Quarter of Belfast City Centre. Left to right. Volunteers Kathryn Lowry from Ballymena and Emma Charles from Fivemiletown. Photo-Jonathan Porter/Presseye.

Sports Minister Caral Ni Chuilin gets to grips with the Garda rugby team at the Dub today, as part of the World Police and Fire Games. Photo-William Cherry/Presseye

Ultimate Firefighter competition at the Titanic Slipway in the Titanic Quarter of Belfast City Centre. Volunteers and sponsor Coke employees Zoe Cunningham(left) Ashley McIntyre(right) with firefighter and Crew Commander Blue Central Danny Ard. Photo-Jonathan Porter/Presseye.

Firefighter Stuart Knight, Cadagan Red Watch, Silver Medalist at the Ultimate Firefighter 30-34 event at the World Police and Fire Games at Titanic Slipway. Photo by Presseye

An ill-tempered football match at the World Police and Fire Games between the PSNI and a Spanish side had to be called off yesterday.

The over-35s game was abandoned after the management and touchline staff from the Marbella Police abused match officials after two of their players were sent off.

The Spanish were leading 3-2 when the first sending off happened after one of their players pushed a PSNI player to the ground.

Another Spaniard then got involved and he too was sent off, which enraged the support team on the sidelines.

They started to abuse the referee and the assistant referee on their side of the pitch.

Despite warnings, they continued to harangue officials. The warnings were ignored and the referee stopped the game after 75 minutes with the Spanish in front.

It is assumed that the Marbella side will lose by default, which would put the PSNI team top of the tournament with the gold medal in sight.

Belfast Telegraph