Ingebrigt Johansson. Ingebrigt Johansson (24 October 1904 – 24 April 1987) was a Norwegian

mathematician A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concerned with numbers, data, quantity, mathematical structure, structure, space, Mathematica ...

. He developed the

symbolic logic Logic is the study of correct reasoning. It includes both formal and informal logic. Formal logic is the study of deductively valid inferences or logical truths. It examines how conclusions follow from premises based on the structure o ...

system known as

minimal logic Minimal logic, or minimal calculus, is a symbolic logic system originally developed by Ingebrigt Johansson. It is an intuitionistic and paraconsistent logic, that rejects both the law of the excluded middle as well as the principle of explosion (' ...

Biography

Johansson was bornin

Narvik () is the third-largest List of municipalities of Norway, municipality in Nordland Counties of Norway, county, Norway, by population. The administrative centre of the municipality is the Narvik (town), town of Narvik. Some of the notable villag ...

, the son of bricklayer Isak Johansson (1849–1941) and Gjertrud Kletten (1865–1948). In 1941 he married Gidske Jacoba Schult (1908–1994). He died in Oslo, Norway on April 24, 1987. In 1923 Johansson entered the

University of Oslo The University of Oslo (; ) is a public university, public research university located in Oslo, Norway. It is the List of oldest universities in continuous operation#Europe, oldest university in Norway. Originally named the Royal Frederick Univ ...

to study mathematics. After he received his Candidatus realium degree in 1928 he continued his studies in

Bonn Bonn () is a federal city in the German state of North Rhine-Westphalia, located on the banks of the Rhine. With a population exceeding 300,000, it lies about south-southeast of Cologne, in the southernmost part of the Rhine-Ruhr region. This ...

in 1929 and in Frankfurt a.M. in 1930 and 1931. In 1931 he received his doctorate ( Dr. philos) from the University of Oslo for his dissertation "Topologische Untersuchungen über unverzweigte Überlagerungsflächen". He spent his professional career at the University of Oslo, from 1931 to 1936 as a fellow in geometry, from 1936 to 1942 as a lecturer in

descriptive geometry Descriptive geometry is the branch of geometry which allows the representation of three-dimensional objects in two dimensions by using a specific set of procedures. The resulting techniques are important for engineering, architecture, design an ...

and finally as a professor of mathematics from 1946 (his appointment dated from 1942). From 1935 to 1946 Johansson served as president of the

Norwegian Mathematical Society The Norwegian Mathematical Society (, NMF) is a professional society for mathematicians. It was formed in 1918, with Carl Størmer elected as its first president. It organizes mathematical contests and the annual Abel symposium and also awards th ...

. He was elected to the

Norwegian Academy of Science and Letters The Norwegian Academy of Science and Letters (, DNVA) is a learned society based in Oslo, Norway. Its purpose is to support the advancement of science and scholarship in Norway. History The Royal Frederick University in Christiania was establis ...

in 1937. He put great effort into mathematical didactics, experimenting with new methods in teaching and introducing new exam forms such as critique and comment tasks. He also wrote several textbooks and worked on curriculum reforms for the Oslo mathematics faculty. He died in

Oslo Oslo ( or ; ) is the capital and most populous city of Norway. It constitutes both a county and a municipality. The municipality of Oslo had a population of in 2022, while the city's greater urban area had a population of 1,064,235 in 2022 ...

References

External links

Matematikklærerne ved Universitetet i Oslo
1904 births 1987 deaths 20th-century Norwegian mathematicians Norwegian people of Swedish descent People from Narvik Presidents of the Norwegian Mathematical Society {{Norway-academic-bio-stub