Reprinted from yesterday's late edition.

"Hi, everybody, the President of the United States said to the President of Mexico as he and his wife arrived at the North Portico, and with that greeting Monday night Jimmy Carter's White House State Dinner for Jose Lopez Portillo was under way.

Punctually, and without panoply, last night's dinner wound up a day noticeably lacking in ceremony, a style Carter has indicated in his three weeks as President that he prefers.

Amy Carter's Siamese cat helped things along a bit when it sneaked down the grand staircase a few minutes before the two Presidents descended enroute to the 100 blacktie dinner guests assembled in the East Room. But the cat, Misty Malarky Ying Yang, apparently thought better of it after getting a good look at the crowd of photographers and reporters waiting in the foyer, turned around and slinked back upstairs at the precise moment Carter and Lopez Portillo were beginning their descent. Both men broke into broad grins.

There were no "Ruffles and Flourishes," no color guard and no herald trumpets as the two couples came to a stop at the bottom of the staircase. Neither had there been an honor guard lining the North Driveway for the arrival of President and Mrs. Lopez Portillo from Blair House.

The one musical concession to the state occasion was the Marine Band playing "Hail to the Chief" when the Carters and Lopez Portillos began their entrance into the East Room.

Generally, though, the tenor of the evening was a marked informality, almost studious avoidance of glamor and absense of pretentiousness in demeanor as well as trappings. The Carter's ruled out after-dinner dancing, striving instead for an early evening that began a half an hour (7:30 p.m.) before most formal dinner parties get under way in Washington. Hard liquor, too, was deleted from the evening although a variety of wines was served.

The Carter family was out almost in force, including Amy, 9, who joined her parents at the round table where the Mexican visitors were seated. Also there were the wife of Mexico's ambassador, Mrs. Hugo Margaim, and Mexico's foreign minister and Mrs. Santiago Roel. Amy wore a long red jumper and white blouse for the occasion.

Amy sat through the dinner reading an Alfred Hitchcock book, "The Mystery of the Screaming Clock." The President of Mexico referred to his in his toast, calling Amy "a lovely and intelligent child." He said the experience of dining with Amy has "facilitated communication with the family in spite of protocol" and that he admired Caryer for being "not only a statesman but a man of solid moral principles . . . who loves his wife."

President Carter said in his after-dinner toast that it was "not an accident" that the Mexican leader would be his first visitor. "Twelve years ago we had the best vacation of our lives" in Mexico he said. "We all can speak a little Spanish and went to small towns and villages where not many people speak English."

The Carters had a hard time with the language, he said, but they remember "those who took us into their hearts and homes." He spoke in Spanish, quoting the Mexican saying: "Poor Mexico so far from God, so close to the United States," and voiced the home that with the new Mexican administration "the distance from God is much less and the proximity to the United States will become a blessing and not a curse."

The Carters entertained their guests and members of the official parties briefly upstairs. When Secretary of State Cyrus Vance and Mrs. Vance descended, they ducked around the corner and down the stairs, presumably to enable Vance to finish preparations for his department Monday night to the Middle East.

Vice President Walter Mondale and Mrs. Mondale, Treasury Secretary W. Michael Blumenthal and Mrs. Blementhal, U.N. Ambassador Andrew J. Young and Mrs. Young and National Security Adviser Zbigniew Brzezinski and Mrs. Brzezinski were among the dinner guests, as were several members of Congress and a trio of state governors.

But in addition to those representing official Washington, the guest list was heavy with former campaign workers or early Carter supporters. Among them was Maryland State Sen. James Clark, who was Carter's Maryland campaign chairman. And from the Democratic National Committee were chairman Kenneth M. Curtis and his predecessor, Robert Strauss.

Pianist Rudolf Serkin was the evening's star entertainer.

After dinner, the "family evening," as OAS Secretary General Alejandro Orfila put it, grew to include another 80 or so guests invited in for the entertainment. They were received by the Carters and the Lopez Portillos in the Great hall as the other guests, finished with coffee, filed into the East Room.

The Carters and the Lopez Portillos talked briefly in the Blue Room, seated before the fireplace and with interpreters at their sides. Nearby, U.N. Ambassador Andrew Young was trying to downplay suggestions by reporters that he and Cyrus Vance might be at odds over Young's remarks about the Cubans in Angola.

"The problem is the press hasn't got used to foreign policy being conducted in the open," said Young.

One guest, who had come for dinner was uncertain how he happened to be invited. He was author Larry McMurtry "whose novels are set in Texas," said one White House aide. McMurtry had no explanation, since he had never met Carter before. "I'm quite baffled," McMurtry said.

After dinner, President Carter asked Mrs. Lopez Portillo to play Rudolph Serkins's piano, which Serkin had had transported especially to the White House for the evening's entertainment. Mrs. Lopez Portillo, who "could have become a concert pianist but then she met the man whom I'm sure she recognized as a future President of Mexico," according to President Carter, and "gave up her career to save an embryonic marriage," played two Chopin pieces.

"I hate to ask Rudolph to follow Mrs. Lopez Portillo," said President Carter in his next introduction, but "You're going to have the chance to hear the best music of our life." Serkin played a Beethoven program.

President Carter said that "8 or 10 hours every day I listen to music similar to what he's going to play tonight." After Serkin's performance, Carter said, "It's almost worth campaigning for years to be able to come here and have this."

Carter then made a small speech of thanks to his guests and bid them goodnight, making perfectly clear the new White House policy of expecting the guests to go home early and not to linger and dance as had been the case at the state dinners of previous administrations. The place cleared out shortly after 11 p.m.